0000000000896581
AUTHOR
Y. Wang
GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences
The LIGO Scientific and Virgo Collaborations have announced the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star background will add to the background from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude $\Omega_{\rm…
Measurements of the branching fractions of $\psi(3686)\rightarrow\bar{\Sigma}^{0}\Lambda+c.c.$ and $\chi_{cJ (J = 0,1,2)} \rightarrow \Lambda \bar{\Lambda}$
Based on $4.481\times10^8$ $\psi(3686)$ events collected with the BESIII detector at BEPCII, the branching fraction of the isospin violating decay $\psi(3686)\rightarrow\bar{\Sigma}^{0}\Lambda+c.c.$ is measured to be $(1.60 \pm 0.31 \pm 0.13~\pm~0.58) \times 10^{-6}$, where the first uncertainty is statistical, the second is systematic, and the third is the uncertainty arising from interference with the continuum. This result is significantly smaller than the measurement based on CLEO-c data sets. The decays $\chi_{cJ} \rightarrow\Lambda\bar{\Lambda}$ are measured via $\psi(3686)\rightarrow\gamma\chi_{cJ}$, and the branching fractions are determined to be $\mathcal{B}\left(\chi_{c0}\rightar…
Measurement of the absolute branching fraction for Λc+→Λμ+νμ
Abstract We report the first measurement of the absolute branching fraction for Λ c + → Λ μ + ν μ . This measurement is based on a sample of e + e − annihilation data produced at a center-of-mass energy s = 4.6 GeV , collected with the BESIII detector at the BEPCII storage rings. The sample corresponds to an integrated luminosity of 567 pb − 1 . The branching fraction is determined to be B ( Λ c + → Λ μ + ν μ ) = ( 3.49 ± 0.46 ( stat ) ± 0.27 ( syst ) ) % . In addition, we calculate the ratio B ( Λ c + → Λ μ + ν μ ) / B ( Λ c + → Λ e + ν e ) to be 0.96 ± 0.16 ( stat ) ± 0.04 ( syst ) .
Cross section measurement of e+e−→pp¯η and e+e−→pp¯ω at center-of-mass energies between 3.773 GeV and 4.6 GeV
Study of the $e^+e^- \to \pi^{+}\pi^{-}\omega$ process at center-of-mass energies between 4.0 and 4.6 GeV
Using $15.6$ $\rm fb^{-1}$ of $e^+e^-$ collision data collected at twenty-four center-of-mass energies from $4.0$ to $4.6$ GeV with the BESIII detector, the helicity amplitudes of the process $e^+e^-\to \pi^{+}\pi^{-}\omega$ are analyzed for the first time. Born cross section measurements of two-body intermediate resonance states with statistical significance greater than 5$\sigma$ are presented, such as $f_{0}(500)$, $f_{0}(980)$, $f_{2}(1270)$, $f_{0}(1370)$, $b_{1}(1235)^{\pm}$, and $\rho(1450)^{\pm}$. In addition, evidence of a resonance state in $e^+e^-\to \pi^+\pi^-\omega$ production is found. The mass of this state obtained by line shape fitting is about 4.2 GeV/$c^2$, which is consi…
Measurement of $\Lambda$ transverse polarization in $e^{+}e^{-}$ collisions at $\sqrt{s}= 3.68-3.71$ GeV
With data samples collected with the BESIII detector at seven energy points at $\sqrt{s}= 3.68 - 3.71$ GeV, corresponding to an integrated luminosity of 333 pb$^{-1}$, we present a study of the $\Lambda$ transverse polarization in the $e^+e^-\to\Lambda\bar\Lambda$ reaction. The significance of polarization by combining the seven energy points is found to be 2.6$\sigma$ including the systematic uncertainty, which implies a non-zero phase between the transition amplitudes of the $\Lambda\bar\Lambda$ helicity states. The modulus ratio and the relative phase of EM-$psionic$ form factors combined with all energy points are measured to be $R^{\Psi} =$ 0.71$^{+0.10}_{-0.10}$ $\pm$ 0.03 and $\Delta…
The global cardiovascular risk transition: associations of four metabolic risk factors with national income, urbanization, and Western diet in 1980 and 2008
Background— It is commonly assumed that cardiovascular disease risk factors are associated with affluence and Westernization. We investigated the associations of body mass index (BMI), fasting plasma glucose, systolic blood pressure, and serum total cholesterol with national income, Western diet, and, for BMI, urbanization in 1980 and 2008. Methods and Results— Country-level risk factor estimates for 199 countries between 1980 and 2008 were from a previous systematic analysis of population-based data. We analyzed the associations between risk factors and per capita national income, a measure of Western diet, and, for BMI, the percentage of the population living in urban areas. In 1980, the…
Measurement of charged jet production cross sections and nuclear modification in p–Pb collisions at sNN=5.02 TeV
Charged jet production cross sections in p–Pb collisions at √sNN = 5.02 TeV measured with the ALICE detector at the LHC are presented. Using the anti-kT algorithm, jets have been reconstructed in the central rapidity region from charged particles with resolution parameters R = 0.2 and R = 0.4. The reconstructed jets have been corrected for detector effects and the underlying event background. To calculate the nuclear modification factor, RpPb, of charged jets in p–Pb collisions, a pp reference was constructed by scaling previously measured charged jet spectra at √s = 7 TeV. In the transverse momentum range 20 ≤ pT, ch jet ≤ 120 GeV/c, RpPb is found to be consistent with unity, indicating th…
Measurement of the Branching Fraction for the Decay $\psi(3686) \rightarrow \phi K_{S}^{0} K_{S}^{0}$
Based on $(448.1 \pm 2.9 )\times 10^6$ $\psi(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decay $\psi(3686)\rightarrow \phi K_{S}^{0} K_{S}^{0}$ is observed for the first time. Taking the interference between $\psi(3686)$ decay and continuum production into account, the branching fraction of this decay is measured to be $\mathcal{B}(\psi(3686)\rightarrow\phi K_S^0 K_S^0 )$ = $(3.53 $ $\pm$ $0.20$ $\pm$ $0.21$)$\times 10^{-5}$, where the first uncertainty is statistical and the second is systematic. Combining with the world average value for ${\mathcal B}(J/\psi\to \phi K^0_SK^0_S)$, the ratio $\mathcal{B}(\psi(3686)\rightarrow \phi K_{S}^{0} K_{S}^{…
Freeze-out radii extracted from three-pion cumulants in pp, p–Pb and Pb–Pb collisions at the LHC
In high-energy collisions, the spatio-temporal size of the particle production region can be measured using the Bose-Einstein correlations of identical bosons at low relative momentum. The source radii are typically extracted using two-pion correlations, and characterize the system at the last stage of interaction, called kinetic freeze-out. In low-multiplicity collisions, unlike in high-multiplicity collisions, two-pion correlations are substantially altered by background correlations, e.g. mini-jets. Such correlations can be suppressed using three-pion cumulant correlations. We present the first measurements of the size of the system at freeze-out extracted from three-pion cumulant correl…
Euclid preparation XV. Forecasting cosmological constraints for the Euclid and CMB joint analysis
The combination and cross-correlation of the upcoming $Euclid$ data with cosmic microwave background (CMB) measurements is a source of great expectation since it will provide the largest lever arm of epochs, ranging from recombination to structure formation across the entire past light cone. In this work, we present forecasts for the joint analysis of $Euclid$ and CMB data on the cosmological parameters of the standard cosmological model and some of its extensions. This work expands and complements the recently published forecasts based on $Euclid$-specific probes, namely galaxy clustering, weak lensing, and their cross-correlation. With some assumptions on the specifications of current and…
First observation of the doubly charmed baryon decay Ξcc++→Ξc+π+
The doubly charmed baryon decay Ξcc++→Ξc+π+ is observed for the first time, with a statistical significance of 5.9σ, confirming a recent observation of the baryon in the Λc+K−π+π+ final state. The data sample used corresponds to an integrated luminosity of 1.7 fb−1, collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Ξcc++ mass is measured to be 3620.6±1.5(stat)±0.4(syst)±0.3(Ξc+) MeV/c2 and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be [B(Ξcc++→Ξc+π+)×B(Ξc+→pK−π+)]/[B(Ξcc++→Λc+K−π+π+)×B(Λc+→pK−π+)]=0.035±0.009(stat)±0.003(syst).
Observation of the decay $D^+_s\to \omega\pi^+\eta$
Using 7.33 fb$^{-1}$ of $e^+e^-$ collision data collected by the BESIII detector at center-of-mass energies between 4.128 and 4.226~GeV, we observe for the first time the decay $D^{\pm}_s\to \omega\pi^{\pm}\eta$ with a statistical significance of 7.6$\sigma$. The measured branching fraction of this decay is $(0.54\pm0.12\pm0.04)\%$, where the first uncertainty is statistical and the second is systematic.
Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background
The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually-unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generic…
Search for invisible decays of the Λ baryon
Physical review / D 105(7), L071101 (2022). doi:10.1103/PhysRevD.105.L071101
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…
Updated measurement of the branching fraction of $D_s^+\to \tau^+\nu_\tau$ via $\tau^+\to\pi^+\bar{\nu}_\tau$
We report the updated study of $D_s^+\to \tau^+\nu$ via $\tau^+\to\pi^+\bar{\nu}_\tau$ with a boosted decision trees analysis, with $7.33$ fb$^{-1}$ of $e^{+}e^{-}$ collision data collected by the BESIII detector at center-of-mass energies between $4.128$ and $4.226$~GeV. The branching fraction of $D_s^+\to \tau^+\nu_\tau$ is determined to be $(5.41\pm0.17_{\rm stat}\pm0.13_{\rm syst})\%$. The product of the $D_s^+$ decay constant $f_{D_s^+}$ and the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cs}|$ is $f_{D_s^+}|V_{cs}| = (247.6\pm3.9_{\rm stat}\pm3.2_{\rm syst}\pm1.0_{\rm input})~\mathrm{MeV}$. Combining with the $|V_{cs}|$ obtained from the global fit in the Standard Model and the $f_{…
Search for a massless dark photon in $\Lambda^{+}_{c}\to p \gamma^{\prime}$ decay
A search for a massless dark photon $\gamma^{\prime}$ is conducted using 4.5 $\mathrm{fb}^{-1}$ of $e^+e^-$ collision data collected at center-of-mass energies between 4.600 and 4.699 $\mathrm{GeV}$ with the BESIII detector at BEPCII. No significant signal is observed, and the upper limit on the branching fraction $\mathcal{B}(\Lambda^{+}_{c}\to p \gamma^{\prime})$ is determined to be $8.0\times 10^{-5}$ at 90% confidence level.
Poster: Polar Dielectrics, Optics, and Ionics
Observation of the hindered electromagnetic Dalitz decay ψ(3686)→e+e−ηc
Physical review / D 106(11), 112002 (2022). doi:10.1103/PhysRevD.106.112002
Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950–2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019
Background Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian…
Search for Higgs Boson Decays into a Z Boson and a Light Hadronically Decaying Resonance Using 13 TeV pp Collision Data from the ATLAS Detector
A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139 fb^{-1} collected at sqrt[s]=13 TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar sector or a charmonium state. Multivariate discriminants are used for the event selection and for evaluating the mass of the light resonance. No excess of events above the expected background is found. Observed (expected) 95% confidence-level upper limits are set on the Higgs boson production cross section times branching fraction to a Z bos…
Measurement of cross sections of the interactions e+e−→ ϕϕω and e+e−→ ϕϕϕ at center-of-mass energies from 4.008 to 4.600 GeV
Abstract Using data samples collected with the BESIII detector at the BEPCII collider at six center-of-mass energies between 4.008 and 4.600 GeV, we observe the processes e + e − → ϕ ϕ ω and e + e − → ϕ ϕ ϕ . The Born cross sections are measured and the ratio of the cross sections σ ( e + e − → ϕ ϕ ω ) / σ ( e + e − → ϕ ϕ ϕ ) is estimated to be 1.75 ± 0.22 ± 0.19 averaged over six energy points, where the first uncertainty is statistical and the second is systematic. The results represent first measurements of these interactions.
Production of Muons from Heavy Flavor Decays at Forward Rapidity inppand Pb-Pb Collisions atsNN=2.76 TeV
The ALICE Collaboration has measured the inclusive production of muons from heavy-flavor decays at forward rapidity, 2.5 < y < 4, in pp and Pb-Pb collisions at root s(NN) = 2.76 TeV. The p(t)-differential inclusive cross section of muons from heavy-flavor decays in pp collisions is compared to perturbative QCD calculations. The nuclear modification factor is studied as a function of p(t) and collision centrality. A weak suppression is measured in peripheral collisions. In the most central collisions, a suppression of a factor of about 3-4 is observed in 6 < p(t) < 10 GeV/c. The suppression shows no significant p(t) dependence.
Feasibility and physics potential of detecting $^8$B solar neutrinos at JUNO
The Jiangmen Underground Neutrino Observatory (JUNO) features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector. Some of JUNO's features make it an excellent location for 8B solar neutrino measurements, such as its low-energy threshold, high energy resolution compared with water Cherenkov detectors, and much larger target mass compared with previous liquid scintillator detectors. In this paper, we present a comprehensive assessment of JUNO's potential for detecting 8B solar neutrinos via the neutrino-electron elastic scattering process. A reduced 2 MeV threshold for the recoil electron energy is found to be achievable, assuming that the intrinsic radioactive …
Measurement of cross section for $e^{+}e^{-}\rightarrow��^{0}\bar��^{0}$ near threshold
Using $e^+e^-$ collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb$^{-1}$, we measure the cross sections and effective form factors for the process $e^{+}e^{-}\rightarrow��^{0}\bar��^{0}$ utilizing a single-tag method. A fit to the cross section of $e^{+}e^{-}\rightarrow��^{0}\bar��^{0}$ with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes $e^{+}e^{-}\rightarrow��^{-}\bar��^{+}$ and $��^{0}\bar��^{0}$ is calculated using recent BESIII mea…
J/ψElliptic Flow in Pb-Pb Collisions atsNN=2.76 TeV
We report on the first measurement of inclusive J/psi elliptic flow v(2) in heavy-ion collisions at the LHC. The measurement is performed with the ALICE detector in Pb-Pb collisions at root s(NN) = 2.76 TeV in the rapidity range 2.5 < y < 4.0. The dependence of the J/psi v(2) on the collision centrality and on the J/psi transverse momentum is studied in the range 0 <= p(T) < 10 GeV/c. For semicentral Pb-Pb collisions at root s(NN) = 2.76 TeV, an indication of nonzero v(2) is observed with a largest measured value of v(2) = 0.116 +/-0.046(stat) +/- 0.029(syst) for J/psi in the transverse momentum range 2 <= p(T) < 4 GeV/c. The elliptic flow measurement complements the previously reported ALI…
Optimization of the JUNO liquid scintillator composition using a Daya Bay antineutrino detector
To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and <0.01 mg/L to 4 g/L and 13 mg/L, respectively. The numbers of total detected photoelectrons suggest that, with the optically purified solvent, the bis-MSB concentration does not need to be more than 4 mg/L. To bridge the one order of magnitude in the detect…
Study of $e^+e^- \rightarrow ��^{0}X(3872)��$ and search for $Z_c(4020)^{0}\rightarrow X(3872)��$
Using data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies from 4.178 to 4.600 GeV, we study the process $e^+e^-\rightarrow��^{0}X(3872)��$ and search for $Z_c(4020)^{0}\rightarrow X(3872)��$. We find no significant signal and set upper limits on $��(e^+e^-\rightarrow��^{0}X(3872)��)\cdot\mathcal{B}(X(3872)\rightarrow��^{+}��^{-}J/��)$ and $��(e^+e^-\rightarrow��^{0}Z_c(4020)^{0})\cdot\mathcal{B}(Z_c(4020)^{0}\rightarrow X(3872)��)\cdot\mathcal{B}(X(3872)\rightarrow��^{+}��^{-}J/��)$ for each energy point at $90\%$ confidence level, which is of the order of several tenths pb.
Performance of prototypes for the ALICE electromagnetic calorimeter
The performance of prototypes for the ALICE electromagnetic sampling calorimeter has been studied in test beam measurements at FNAL and CERN. A $4\times4$ array of final design modules showed an energy resolution of about 11% /$\sqrt{E(\mathrm{GeV})}$ $\oplus$ 1.7 % with a uniformity of the response to electrons of 1% and a good linearity in the energy range from 10 to 100 GeV. The electromagnetic shower position resolution was found to be described by 1.5 mm $\oplus$ 5.3 mm /$\sqrt{E \mathrm{(GeV)}}$. For an electron identification efficiency of 90% a hadron rejection factor of $>600$ was obtained.
Examining the generalizability of research findings from archival data
This research project benefitted from Ministry of Education (Singapore) Tier 1 Grant R-313-000-131-115 (to A. Delios), National Science Foundation of China Grants 72002158 (to H.T.) and 71810107002 (to H.T.), grants from the Knut and Alice Wallenberg Foundation (to A. Dreber) and the Marianne and Marcus Wallenberg Foundation (through a Wallenberg Scholar grant; to A. Dreber), Austrian Science Fund (FWF) Grant SFB F63 (to A. Dreber), grants from the Jan Wallander and Tom Hedelius Foundation (Svenska Handelsbankens Forskningsstiftelser; to A. Dreber), and an Research & Development (R&D) research grant from Institut Européen d'Administration des Affaires (INSEAD) (to E.L.U.). Dmitrii Dubrov, o…
Measurement of $Λ$ transverse polarization in $e^{+}e^{-}$ collisions at $\sqrt{s}= 3.68-3.71$ GeV
With data samples collected with the BESIII detector at seven energy points at $\sqrt{s}= 3.68 - 3.71$ GeV, corresponding to an integrated luminosity of 333 pb$^{-1}$, we present a study of the $Λ$ transverse polarization in the $e^+e^-\toΛ\barΛ$ reaction. The significance of polarization by combining the seven energy points is found to be 2.6$σ$ including the systematic uncertainty, which implies a non-zero phase between the transition amplitudes of the $Λ\barΛ$ helicity states. The modulus ratio and the relative phase of EM-$psionic$ form factors combined with all energy points are measured to be $R^Ψ =$ 0.71$^{+0.10}_{-0.10}$ $\pm$ 0.03 and $ΔΦ^Ψ$ = (23$^{+8.8}_{-8.0}$ $\pm$ 1.6$)^\circ$…
Pseudorapidity Density of Charged Particles inp+PbCollisions atsNN=5.02 TeV
The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsingle-diffractive p + Pb collisions at a center-of-mass energy per nucleon pair root s(NN) = 5.02 TeV is presented. The average value at midrapidity is measured to be 16.81 +/- 0.71 (syst), which corresponds to 2.14 +/- 0.17 (syst) per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsingle-diffractive pp collisions interpolated to the same collision energy and 84% higher than in d + Au collisions at root s(NN) = 0.2 TeV. The measured pseudorapidity density in p + Pb collisions is compared to model predictions and provides new constraints on the description of …
The ALICE Transition Radiation Detector: Construction, operation, and performance
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/$c$ in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both …
Centrality, rapidity and transverse momentum dependence of J/ψ suppression in Pb–Pb collisions at sNN=2.76 TeV
The inclusive J/.nuclear modification factor (R-AA) in Pb-Pb collisions at root(NN)-N-S = 2.76TeVhas been measured by ALICE as a function of centrality in the e+ e-decay channel at mid-rapidity (| y| < 0.8) and as a function of centrality, transverse momentum and rapidity in the + -decay channel at forward-rapidity (2.5 < y < 4). The J/.yields measured in Pb-Pb are suppressed compared to those in ppcollisions scaled by the number of binary collisions. The RAAintegrated over a centrality range corresponding to 90% of the inelastic Pb-Pb cross section is 0.72 - 0.06(stat.) - 0.10(syst.) at mid-rapidity and 0.58 - 0.01(stat.) - 0.09(syst.) at forward-rapidity. At low transverse momentum, signi…
New information on 12C states from the decays of 12N and 12B
Abstract The properties of states in 12 C above the 3α-threshold are of high current interest for nuclear astrophysics and for the nuclear many-body problem in general. We have initiated a series of experiments aimed at elucidating this region by using the β-decays of 12 N and 12 B. By applying the ISOL method for producing these radioactive isotopes, in combination with modern segmented charged particle detectors, our approach has significant advantages over previous studies of this region.
Partial wave analysis of $J / ψ → γ η η ′$
Physical review / D 105(7), 072002 (2022). doi:10.1103/PhysRevD.105.072002
Calibration strategy of the JUNO experiment
We present the calibration strategy for the 20 kton liquid scintillator central detector of the Jiangmen Underground Neutrino Observatory (JUNO). By utilizing a comprehensive multiple-source and multiple-positional calibration program, in combination with a novel dual calorimetry technique exploiting two independent photosensors and readout systems, we demonstrate that the JUNO central detector can achieve a better than 1% energy linearity and a 3% effective energy resolution, required by the neutrino mass ordering determination. [Figure not available: see fulltext.]
Determination of the absolute branching fractions of D0→K−e+νe and D+→K¯0e+νe
Updated determination of D0–D¯0 mixing and CP violation parameters with D0→K+π− decays
We report measurements of charm-mixing parameters based on the decay-time-dependent ratio of D0→K+π- to D0→K-π+ rates. The analysis uses a data sample of proton-proton collisions corresponding to an integrated luminosity of 5.0 fb-1 recorded by the LHCb experiment from 2011 through 2016. Assuming charge-parity (CP) symmetry, the mixing parameters are determined to be x′2=(3.9±2.7)×10-5, y′=(5.28±0.52)×10-3, and RD=(3.454±0.031)×10-3. Without this assumption, the measurement is performed separately for D0 and D¯0 mesons, yielding a direct CP-violating asymmetry AD=(-0.1±9.1)×10-3, and magnitude of the ratio of mixing parameters 1.00<|q/p|<1.35 at the 68.3% confidence level. All results incl…
KS0andΛProduction in Pb-Pb Collisions atsNN=2.76 TeV
The ALICE measurement of K^0_S and {\Lambda} production at mid-rapidity in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and in the pT range from 0.4 GeV/c (0.6 GeV/c for {\Lambda}) to 12 GeV/c. The pT dependence of the {\Lambda}/K^0_S ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher pT with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not observed in pp interactions at sqrt(s) = 0.9 Te…
First measurement of polarizations in the decay $D^0 \to ωϕ$
Using a data sample corresponding to an integrated luminosity of 2.93 fb$^{-1}$ collected at a center-of-mass energy $\sqrt{s}=3.773$ GeV by the BESIII detector, the decay $D^0 \toωϕ$ is observed for the first time. The branching fraction is measured to be $(6.48 \pm 0.96 \pm 0.40)\times 10^{-4}$ with a significance of $6.3 σ$, where the first and second uncertainties are statistical and systematic, respectively. An angular analysis reveals that the $ϕ$ and $ω$ mesons from the $D^0 \to ωϕ$ decay are transversely polarized. The $95\%$ confidence level upper limit on longitudinal polarization fraction is set to be less than $0.24$, which is inconsistent with current theoretical expectations a…
Improved measurement of the absolute branching fraction of inclusive semileptonic Λc+ decay
Using 4.5 fb−1 of e+e− annihilation data samples collected at center-of-mass energies ranging from 4.600 to 4.698 GeV with the BESIII detector at the BEPCII collider, we measured the absolute branching fraction for the inclusive semileptonic decay Λc+→Xe+νe, where X refers to any possible particle system. The branching fraction of the decay is determined to be B(Λc+→Xe+νe)=(4.06±0.10stat±0.09syst)%. Our result improves the precision of previous measurements of B(Λc+→Xe+νe) by more than threefold. Using the known Λc+ lifetime and the charge-averaged semileptonic decay width of nonstrange charmed mesons, we measure the ratio of inclusive semileptonic decay widths Γ(Λc+→Xe+νe)/Γ¯(D→Xe+νe)=1.28…
Amplitude analysis and branching-fraction measurement of \boldmath $D_{s}^{+} \to K^0_{S}\pi^{+}\pi^{0}$
Utilizing a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{-1}$, recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we perform an amplitude analysis of the decay $D_{s}^{+} \to K_{S}^{0}\pi^{+}\pi^{0}$ and determine the relative fractions and phase differences of different intermediate processes, which include $K_{S}^{0}\rho(770)^{+}$, $K_{S}^{0}\rho(1450)^{+}$, $K^{*}(892)^{0}\pi^{+}$, $K^{*}(892)^{+}\pi^{0}$, and $K^{*}(1410)^{0}\pi^{+}$. Using a double-tag technique, and making an efficiency correction that relies on our knowledge of the phase-space distribution of the decays coming from the amplitude analysis, the absolute branch…
Aerosol optical properties and direct radiative forcing based on measurements from the China Aerosol Remote Sensing Network (CARSNET) in eastern China
Aerosol pollution in eastern China is an unfortunate consequence of the region's rapid economic and industrial growth. Here, sun photometer measurements from seven sites in the Yangtze River Delta (YRD) from 2011 to 2015 were used to characterize the climatology of aerosol microphysical and optical properties, calculate direct aerosol radiative forcing (DARF) and classify the aerosols based on size and absorption. Bimodal size distributions were found throughout the year, but larger volumes and effective radii of fine-mode particles occurred in June and September due to hygroscopic growth and/or cloud processing. Increases in the fine-mode particles in June and September caused AOD440 nm &…
Measurement of CP asymmetry in Bs0 → Ds ∓K± decays
Journal of high energy physics 2018(3), 59 (2018). doi:10.1007/JHEP03(2018)059
Harmonic decomposition of two particle angular correlations in Pb–Pb collisions at sNN=2.76 TeV
Angular correlations between unidentified charged trigger (t) and associated (a) particles are measured by the ALICE experiment in Pb-Pb collisions at root s(NN) = 2.76 TeV for transverse momenta 0.25 p(T)(a). The shapes of the pair correlation distributions are studied in a variety of collision centrality classes between 0 and 50% of the total hadronic cross section for particles in the pseudorapidity interval |eta| 0.8, and are referred to as "long-range correlations". Fourier components V-n Delta equivalent to are extracted from the long-range azimuthal correlation functions. If particle pairs are correlated to one another through their individual correlation to a common symmetry plane, …
Excited states in 31S studied via beta decay of 31Cl
The beta decay of 31Cl has been studied with a silicon detector array and a HPGe detector at the IGISOL facility. Previously controversial proton peaks have been confirmed to belong to 31Cl and a new proton group with an energy of 762(14) keV has been found. Proton captures to this state at 6921(15) keV in 31S can have an effect on the reaction rate of 30P(p,γ) in ONe novae. Gamma rays of 1249.1(14) keV and 2234.5(8) keV corresponding to the de-excitations of the first two excited states in 31S have been measured. No beta-delayed protons from the IAS have been observed. peerReviewed
Global, regional, and national progress towards Sustainable Development Goal 3.2 for neonatal and child health: all-cause and cause-specific mortality findings from the Global Burden of Disease Study 2019
Background: Sustainable Development Goal 3.2 has targeted elimination of preventable child mortality, reduction of neonatal death to less than 12 per 1000 livebirths, and reduction of death of children younger than 5 years to less than 25 per 1000 livebirths, for each country by 2030. To understand current rates, recent trends, and potential trajectories of child mortality for the next decade, we present the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 findings for all-cause mortality and cause-specific mortality in children younger than 5 years of age, with multiple scenarios for child mortality in 2030 that include the consideration of potential effects of COVID-…
Precise Measurement of the e(+)e(-) ->pi(+)pi(-) J/psi Cross Section at Center-of-Mass Energies from 3.77 to 4.60 GeV
The cross section for the process e(+)e(-)-> pi(+) pi(-) J/psi is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9 fb(-1) of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (222.0 +/- 3.1 +/- 1.4) MeV/ c(2) and a width of (44.1 +/- 4.3 +/- 2.0)MeV, while the second one has a mass of (4320.0 +/- 10.4 +/- 7.0)MeV/c(2) and a width of (101.4(- 19.7)(+25.3) +/- 10.2) MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The prec…
Feasibility study for the measurement of πN transition distribution amplitudes at P¯ANDA in p¯p→J/ψπ0
The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is show…
Observation of the Leptonic Decay $D^+ → τ^+ ν_τ$
Physical review letters 123(21), 211802 (2019). doi:10.1103/PhysRevLett.123.211802
Long-range angular correlations of π, K and p in p–Pb collisions at sNN=5.02 TeV
Angular correlations between unidentified charged trigger particles and various species of charged associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the transverse-momentum range 0.3 < p(T) < 4 GeV/c. The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range vertical bar n(lab)vertical bar < 0.8. Fourier coefficients are extracted from the long-range correlations projected onto the azimuthal angle difference and studied as a function of p(T) and in intervals of event multiplicity. In high-multipl…
ϕ-Meson production at forward rapidity in p–Pb collisions at sNN=5.02 TeV and in pp collisions at s=2.76 TeV
The first study of $\phi$-meson production in p–Pb collisions at forward and backward rapidity, at a nucleon– nucleon centre-of-mass energy $\sqrt{S_{NN}}$= 5.02 TeV, has been performed with the ALICE apparatus at the LHC. The $\phi$-mesons have been identified in the dimuon decay channel in the transverse momentum ($p_T$) range 1 < $p_T$ < 7 GeV/c, both in the p-going (2.03 < y < 3.53) and the Pb-going (−4.46 < y < −2.96) directions — where $y$ stands for the rapidity in the nucleon–nucleon centre-of-mass — the integrated luminosity amounting to 5.01 ± 0.19 nb$^{−1}$ and 5.81 ± 0.20 nb$^{−1}$ , respectively, for the two data samples. Differential cross sections as a function of transverse …
Euclid preparation - XVII. Cosmic Dawn Survey: Spitzer Space Telescope observations of the Euclid deep fields and calibration fields
Artículo escrito por un elevado núnmero de autores, sólo se referencian el qque aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiere
J/ψSuppression at Forward Rapidity in Pb-Pb Collisions atsNN=2.76 TeV
The ALICE experiment has measured the inclusive J/psi production in Pb-Pb collisions at root s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/psi yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 +/- 0.032(stat) +/- 0.083dsyst_ and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/psi production from charm quarks in…
First simultaneous measurement of $\Xi^0$ and $\bar{\Xi}^0$ asymmetry parameters in $\psi(3686)$ decay
The $\Xi^0$ asymmetry parameters are measured using entangled quantum $\Xi^0$-$\bar{\Xi}^0$ pairs from a sample of $(448.1 \pm 2.9) \times 10^6$ $\psi(3686)$ events collected with the BESIII detector at BEPCII. The relative phase between the transition amplitudes of the $\Xi^0 \bar{\Xi}^0$ helicity states is measured to be $\Delta \Phi = -0.050 \pm 0.150 \pm 0.020$~rad, which implies that there is no obvious polarization at the current level of statistics. The decay parameters of the $\Xi^0$ hyperon $(\alpha_{\Xi^0}, \alpha_{\bar{\Xi}^0}, \phi_{\Xi^0}, \phi_{\bar{\Xi}^0})$ and the angular distribution parameter $(\alpha_{\psi(3686)})$ and $\Delta \Phi$ are measured simultaneously for the fi…
Measurement of the doubly Cabibbo-suppressed decay $D^+\to K^+��^+��^-��^0$ with semileptonic tags
Using an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93\,\rm fb^{-1}$ collected at a center-of-mass energy of 3.773 GeV with the BESIII detector, the doubly Cabibbo-suppressed decay $D^+\to K^+��^+��^-��^0$ is studied with a semileptonic tag method. After removing the decays containing narrow intermediate resonances, $D^+\to K^+��$, $D^+\to K^+��$, and $D^+\to K^+��$, the branching fraction for the decay $D^+\to K^+��^+��^-��^0$ is determined to be $(1.03 \pm 0.12_{\rm stat} \pm 0.06_{\rm syst})\times 10^{-3}$. The ratio of the branching fraction for $D^+\to K^+��^+��^-��^0$ to its Cabibbo-favored counterpart $D^+\to K^-��^+��^+��^0$ is measured to be $…
Measurement of the Dynamics of the Decays Ds+→η(′)e+νe
PubMed ID: 30978074
Evidence of a Resonant Structure in the Cross Section between 4.05 and 4.60 GeV
The cross section of the process e^{+}e^{-}→π^{+}D^{0}D^{*-} for center-of-mass energies from 4.05 to 4.60 GeV is measured precisely using data samples collected with the BESIII detector operating at the BEPCII storage ring. Two enhancements are clearly visible in the cross section around 4.23 and 4.40 GeV. Using several models to describe the dressed cross section yields stable parameters for the first enhancement, which has a mass of 4228.6±4.1±6.3 MeV/c^{2} and a width of 77.0±6.8±6.3 MeV, where the first uncertainties are statistical and the second ones are systematic. Our resonant mass is consistent with previous observations of the Y(4220) state and the theoretical prediction of a D…
Increased dopamine level enhances male-male courtship in Drosophila
1529-2401 (Electronic) Journal Article Research Support, Non-U.S. Gov't; Sexual behavior between males is observed in many species, but the biological factors involved are poorly known. In mammals, manipulation of dopamine has revealed the role of this neuromodulator on male sexual behavior. We used genetic and pharmacological approaches to manipulate the dopamine level in dopaminergic cells in Drosophila and investigated the consequence of this manipulation on male-male courtship behavior. Males with increased dopamine level showed enhanced propensity to court other males but did not change their courtship toward virgin females, general olfactory response, general gustatory response, or lo…
Cross section measurement of e+e−→π+π−ψ(3686) from s=4.0076 GeV to 4.6984 GeV
Search for weakly decaying Λn‾ and ΛΛ exotic bound states in central Pb–Pb collisions at sNN=2.76 TeV
We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible (Lambda n) over bar bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at root S-NN = 2.76 TeV, by invariant mass analysis in the decay modes (Lambda n) over bar (d) over bar pi(+) and H-dibaryon -> Lambda p pi(-). No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound s…
Measurement of the inclusive branching fraction for ψ(3686)→KS0+anything
Abstract Using 5.9 pb−1 of e + e − annihilation data collected at center-of-mass energies from 3.640 to 3.701 GeV with the BESIII detector at the BEPCII Collider, we measure the observed cross sections of e + e − → K S 0 X (where X = anything ). From a fit to these observed cross sections with the sum of continuum and ψ ( 3686 ) and J / ψ Breit-Wigner functions and considering initial state radiation and the BEPCII beam energy spread, we obtain for the first time the product of ψ ( 3686 ) leptonic width and inclusive decay branching fraction Γ ψ ( 3686 ) e e B ( ψ ( 3686 ) → K S 0 X ) = ( 373.8 ± 6.7 ± 20.0 ) eV, and assuming Γ ψ ( 3686 ) e e is ( 2.33 ± 0.04 ) keV from PDG value, we measur…
News on 12C from beta-decay studies
We discuss the importance of the spectroscopic properties of the resonances of 12C just above the 3α-threshold, and review the existing experimental information of this region with emphasis on O+ and 2+ states. A new experimental approach for studying the β-decays of 12B and 12N is presented based on techniques developed in the context of Radioactive beam (rare isotope) physics. Finally preliminary results from an ongoing analysis of two recent experiments are given. © 2004 Published by Elsevier B.V.
Measurement of Proton Electromagnetic Form Factors in e+e−→pp¯ in the Energy Region 2.00–3.08 GeV
The process of e+e−→pp¯ is studied at 22 center-of-mass energy points (s) from 2.00 to 3.08 GeV, exploiting 688.5 pb−1 of data collected with the BESIII detector operating at the BEPCII collider. The Born cross section (σpp¯) of e+e−→pp¯ is measured with the energy-scan technique and it is found to be consistent with previously published data, but with much improved accuracy. In addition, the electromagnetic form-factor ratio (|GE/GM|) and the value of the effective (|Geff|), electric (|GE|), and magnetic (|GM|) form factors are measured by studying the helicity angle of the proton at 16 center-of-mass energy points. |GE/GM| and |GM| are determined with high accuracy, providing uncertaintie…
Improved measurement of the branching fractions of the inclusive decays $D^+ \to K_S^0X $ and $D^0 \to K_S^0X $
By analyzing 2.93 fb$^{-1}$ of $e^+e^-$ collision data taken at the center-of-mass energy of 3.773 GeV with the BESIII detector, the branching fractions of the inclusive decays $D^+\to K^0_S X$ and $D^0\to K^0_S X$ are measured to be $(32.78\pm 0.13\pm 0.27)\%$ and $(20.54\pm 0.12\pm 0.18)\%$, respectively, where the first uncertainties are statistical and the second are systematic. These results are consistent with the world averages of previous measurements, but with improved precision.
Amplitude analysis and branching-fraction measurement of \boldmath $D_{s}^{+} \to K^0_{S}��^{+}��^{0}$
Utilizing a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{-1}$, recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we perform an amplitude analysis of the decay $D_{s}^{+} \to K_{S}^{0}��^{+}��^{0}$ and determine the relative fractions and phase differences of different intermediate processes, which include $K_{S}^{0}��(770)^{+}$, $K_{S}^{0}��(1450)^{+}$, $K^{*}(892)^{0}��^{+}$, $K^{*}(892)^{+}��^{0}$, and $K^{*}(1410)^{0}��^{+}$. Using a double-tag technique, and making an efficiency correction that relies on our knowledge of the phase-space distribution of the decays coming from the amplitude analysis, the absolute branching fract…
Performance of the upgraded PreProcessor of the ATLAS Level-1 Calorimeter Trigger
The PreProcessor of the ATLAS Level-1 Calorimeter Trigger prepares the analogue trigger signals sent from the ATLAS calorimeters by digitising, synchronising, and calibrating them to reconstruct transverse energy deposits, which are then used in further processing to identify event features. During the first long shutdown of the LHC from 2013 to 2014, the central components of the PreProcessor, the Multichip Modules, were replaced by upgraded versions that feature modern ADC and FPGA technology to ensure optimal performance in the high pile-up environment of LHC Run 2. This paper describes the features of the newMultichip Modules along with the improvements to the signal processing achieved.
Association Between Tumor Egfr and Kras Mutation Status and Clinical Outcomes in Nsclc Patients Randomized to Sorafenib Plus Best Supportive Care (BSC) or Bsc Alone: Subanalysis of the Phase III Mission Trial
ABSTRACT Background Tumor EGFR and KRas mutations are both predictive and prognostic biomarkers in patients with advanced NSCLC. We analyzed the correlation between these biomarkers and treatment outcomes in a phase III trial of 3rd/4th line sorafenib in patients with NSCLC. Methods The global, randomized, placebo-controlled MISSION trial enrolled 703 patients with advanced relapsed/refractory NSCLC of predominantly non-squamous histology. The primary study endpoint was overall survival (OS). EGFR and KRas mutations were analyzed in archival tumor samples and in circulating tumor DNA isolated from plasma. Results Tumor and/or plasma mutation data were available from 347 patients (49%). EGFR…
Study of the Decay D+s → π+π+π−η and Observation of the W-annihilation Decay D+s → a0(980)+ρ0
Studying exotic nuclides close to the N = Z line at the HIGISOL facility
The ion guide [1, 2] for heavy-ion fusion-evaporation reactions (HIGISOL) which was developed by Beraud et al. [3] has been implemented at the IGISOL facility in Jyvaskyla [4]. This system was modified over the past 5 years. Figure 1 shows the present set-up. The HIGISOL takes advantage of the different angular distributions of primary beam and reaction products: the primary beam is stopped in front of the stopping chamber and the reaction products enter the stopping chamber through a thin foil passing the beam stop. This so called “shadow” method removes the plasma effect since the primary beam is not ionising the stopping gas. In order to improve ion optical properties, mainly to reduce t…
Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at sNN=2.76 TeV
Transverse momentum spectra of pi(+/-), K-+/- and p((p) over bar) up to p(T) = 20 GeV/c at mid-rapidity in pp, peripheral (60-80%) and central (0-5%) Pb-Pb collisions at v root s(NN) = 2.76 TeV have been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pionratios both show a distinct peak at p(T) approximate to 3 GeV/c in central Pb-Pb collisions. Below the peak, p(T) 10 GeV/c particle ratios in pp and Pb-Pb collisions are in agreement and the nuclear modification factors for pi(+/-), K-+/- and p((p) over bar) indicate that, within the systematic and statistical uncertainties, the suppression is the same. This suggests that the chemical comp…
Study of Open-Charm Decays and Radiative Transitions of the X(3872)
The processes X(3872)→D*0D¯0+c.c.,γJ/ψ,γψ(2S), and γD+D− are searched for in a 9.0 fb−1 data sample collected at center-of-mass energies between 4.178 and 4.278 GeV with the BESIII detector. We observe X(3872)→D*0D0¯+c.c. and find evidence for X(3872)→γJ/ψ with statistical significances of 7.4σ and 3.5σ, respectively. No evident signals for X(3872)→γψ(2S) and γD+D− are found, and the upper limit on the relative branching ratio Rγψ≡{B[X(3872)→γψ(2S)]}/{B[X(3872)→γJ/ψ]}<0.59 is set at 90% confidence level. Measurements of branching ratios relative to decay X(3872)→π+π−J/ψ are also reported for decays X(3872)→D*0D0¯+c.c.,γψ(2S),γJ/ψ, and γD+D−, as well as the non-D*0D0¯ three-body decays π0…
Measurement of the absolute branching fractions for purely leptonic D+s decays
We report new measurements of the branching fraction $\cal B(D_s^+\to \ell^+\nu)$, where $\ell^+$ is either $\mu^+$ or $\tau^+(\to\pi^+\bar{\nu}_\tau)$, based on $6.32$ fb$^{-1}$ of electron-positron annihilation data collected by the BESIII experiment at six center-of-mass energy points between $4.178$ and $4.226$ GeV. Simultaneously floating the $D_s^+\to\mu^+\nu_\mu$ and $D_s^+\to\tau^+\nu_\tau$ components yields $\cal B(D_s^+\to \tau^+\nu_\tau) = (5.21\pm0.25\pm0.17)\times10^{-2}$, $\cal B(D_s^+\to \mu^+\nu_\mu) = (5.35\pm0.13\pm0.16)\times10^{-3}$, and the ratio of decay widths $R=\frac{\Gamma(D_s^+\to \tau^+\nu_\tau)}{\Gamma(D_s^+\to \mu^+\nu_\mu)} = 9.73^{+0.61}_{-0.58}\pm 0.36$, whe…
Behind the Scenes of Scenario-Based Training: Understanding Scenario Design and Requirements in High-Risk and Uncertain Environments
Simulation exercises as a training tool for enhancing preparedness for emergency response are widely adopted in disaster management. This paper addresses current scenario design processes, proposes an alternative approach for simulation exercises and introduces a conceptual design of an adaptive scenario generator. Our work is based on a systematic literature review and observations made during TRIPLEX-2016 exercise in Farsund, Norway. The planning process and scenario selection of simulation exercises impact directly the effectiveness of intra- and interorganizational cooperation. However, collective learning goals are rarely addressed and most simulations are focused on institution-specif…
R-matrix analysis of theβdecays ofN12andB12
The β decays of 12N and 12B have been studied at KVI and JYFL to resolve the composition of the broad and interfering 0+ and 2+ strengths in the triple-α continuum. For the first time a complete treatment of 3α decay is presented including all major breakup channels. A multilevel, many-channel R-matrix formalism has been developed for the complete description of the breakup in combination with the recently published separate analysis of angular correlations. We find that, in addition to the Hoyle state at 7.65 MeV, more than one 0+ and 2+ state is needed to reproduce the spectra. Broad 03+ and 22+ states are found between 10.5 and 12 MeV in this work. The presence of β strength up to the 12…
Observation of $e^{+}e^{-}\rightarrow\eta\psi(2S)$ at center-of-mass energies from 4.236 to 4.600 GeV
Using a total of $5.25~{\rm fb}^{-1}$ of $e^{+}e^{-}$ collision data with center-of-mass energies from 4.236 to 4.600 GeV, we report the first observation of the process $e^{+}e^{-}\to \eta\psi(2S)$ with a statistical significance of $5\sigma$. The data sets were collected by the BESIII detector operating at the BEPCII storage ring. We measure the yield of events integrated over center-of-mass energies and also present the energy dependence of the measured cross section.
Measurements of the center-of-mass energies of e+e- collisions at BESIII
Chinese physics / C 45(10), 103001 (2021). doi:10.1088/1674-1137/ac1575
Comparaison de la mesure des déformations de fantômes de l’aorte à partir d’image obtenues par IRM et stéréovision
International audience; The study of the wall strain distribution could be helpful to improve the decision criterion for surgery of aortic aneurysm. Recently, numerical simulations can complete the data obtained from imaging measurement in order to develop reliable models. However, the used medical imaging tools are not experimentally validated, in metrological point of view. The aim of this study focused on accuracy and reliability of measurement obtained from kinetic MR sequences. The measures of deformations from MRI were compare to those obtained from stereovision system. Cylindrical phantom of silicone material similar to arterial behavior simulated a symmetric aneurysm was designed. A…
First Observation of the Semileptonic Decay $\Lambda_c^+\rightarrow pK^- e^+\nu_e$
Using $4.5~\mathrm{fb}^{-1}$ of $e^+e^-$ annihilation data samples collected at the center-of-mass energies ranging from 4.600~GeV to 4.699~GeV with the BESIII detector at the BEPCII collider, a first study of the semileptonic decays $\Lambda_c^+\rightarrow pK^-e^+\nu_e$, $\Lambda_c^+\rightarrow \Lambda(1520) e^+\nu_e$ and $\Lambda_c^+\rightarrow \Lambda(1405) e^+\nu_e$ is performed. The $\Lambda_c^+\rightarrow pK^-e^+\nu_e$ decay is observed with a significance of $8.2\sigma$ and the branching fraction is measured to be $\mathcal{B}(\Lambda_c^+\rightarrow pK^- e^+\nu_e)=(0.88\pm0.17_{\rm stat.}\pm0.07_{\rm syst.})\times 10^{-3}$. We also report evidence of $\Lambda_c^+\rightarrow \Lambda(1…
J/ψ production as a function of charged particle multiplicity in pp collisions at s =7 TeV
The ALICE Collaboration reports the measurement of the relative J/psi yield as a function of charged particle pseudorapidity density dN(ch)/d eta in pp collisions at root s = 7 TeV at the LHC. J/psi particles are detected for p(t) > 0, in the rapidity interval vertical bar y vertical bar 0. In the highest multiplicity interval with (dN(ch)/d eta)(bin)) = 24.1, corresponding to four times the minimum bias multiplicity density, an enhancement relative to the minimum bias J/psi yield by a factor of about 5 at 2.5 < y <4 (8 at vertical bar y vertical bar < 0.9) is observed. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.
Measurement of the absolute branching fraction of inclusive semielectronic $D_s^+$ decays
We measure the inclusive semielectronic decay branching fraction of the $D_s^+$ meson. A double-tag technique is applied to $e^+e^-$ annihilation data collected by the BESIII experiment at the BEPCII collider, operating in the center-of-mass energy range $4.178 - 4.230$ GeV. We select positrons from $D_s^+\rightarrow Xe^{+}\nu_e$ with momenta greater than 200 MeV/$c$, and determine the laboratory momentum spectrum, accounting for the effects of detector efficiency and resolution. The total positron yield and semielectronic branching fraction are determined by extrapolating this spectrum below the momentum cutoff. We measure the $D_s^+$ semielectronic branching fraction to be $\mathcal{B}\le…
Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurement…
Measurement of the Absolute Branching Fraction of the Inclusive Decay Λc+ → Λ+X
Physical review letters 121(6), 062003 (2018). doi:10.1103/PhysRevLett.121.062003
Light vector meson production in pp collisions at s=7 TeV
The ALICE experiment has measured low-mass dimuon production in pp collisions at root s = 7 TeV in the dimuon rapidity region 2.5 < y < 4. The observed dimuon mass spectrum is described as a superposition of resonance decays (eta, rho, omega, eta', phi) into muons and semi-leptonic decays of charmed mesons. The measured production cross sections for omega and phi are sigma(omega)(1 < p(t) < 5 GeV/c. 2.5 < y < 4) = 5.28 +/- 0.54(stat) +/- 0.49(syst) mb and sigma(phi)(1 < p(t) < 5 GeV/c. 2.5 < y < 4) = 0.940 +/- 0.084(stat) +/- 0.076(syst) mb. The differential cross sections d(2)sigma/dy dp(t) are extracted as a function of p(t) for omega and phi. The ratio between the rho and omega cross sec…
Search for the rare semi-leptonic decay $J/\psi\to D^{-}e^{+}\nu_{e}+c.c.$
Using $10.1\times10^{9}$ $J/\psi$ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $\sqrt{s}=3.097~\rm{GeV}$ and collected with the BESIII detector, we present a search for the rare semi-leptonic decay $J/\psi\to D^{-}e^{+}\nu_{e}+c.c.$. No excess of signal above background is observed, and an upper limit on the branching fraction $\mathcal{B}(J/\psi\to D^{-}e^{+}\nu_{e}+c.c.)<7.1\times10^{-8}$ is obtained at $90\%$ confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.
Medium-spin structure of neutron-rich Pd and Cd isotopes
Cadmium isotopes are traditionally considered as good examples of nearly spherical, vibrational nuclei, which can be described by quadrupole vibrators in the collective model, as well as the U(5) dynamical symmetry in the interacting boson model (IBM). However, the shape coexistence of more deformed intruder states originating from proton 2p–4h excitation across the Z = 50 major shell is another interesting structural aspect, whose presence in Pd-isotopes has also been demonstrated [1,2].
Precision Measurement of the Decay $\Sigma^{+} \rightarrow p\gamma$ in the Process $J/\psi\rightarrow \Sigma^{+}\bar{\Sigma}^{-}$
Using $(10\:087\pm44)\times10^{6}$ $J/\psi$ events collected with the BESIII detector, the radiative hyperon decay $\Sigma\rightarrow p\gamma$ is studied at an electron-positron collider experiment for the first time. The absolute branching fraction is measured to be $\left(0.996 \pm 0.021_{\rm stat.}\pm 0.018_{\rm syst.}\right)\times 10^{-3}$, which is lower than its world average value by $4.2$ standard deviations. Its decay asymmetry parameter is determined to be $-0.652 \pm 0.056_{\rm stat.}\pm 0.020_{\rm syst.}$. The branching fraction and decay asymmetry parameter are the most precise to date, and the accuracies are improved by $78\%$ and $34\%$, respectively.
Net-charge fluctuations in Pb-Pb collisions at sqrt[sNN]=2.76TeV.
We report the first measurement of the net-charge fluctuations in Pb-Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV, measured with the ALICE detector at the CERN Large Hadron Collider. The dynamical fluctuations per unit entropy are observed to decrease when going from peripheral to central collisions. An additional reduction in the amount of fluctuations is seen in comparison to the results from lower energies. We examine the dependence of fluctuations on the pseudo-rapidity interval, which may account for the dilution of fluctuations during the evolution of the system. We find that the ALICE data points are between the theoretically predicted values for a hadron gas and a Quark-Gluon Plasma.…
Amplitude analysis and branching-fraction measurement of Ds+ → KS0 K-π+π+
Search for weakly decaying b -flavored pentaquarks
Investigations of the existence of pentaquark states containing a single $b$ (anti)quark decaying weakly into four specific final states J/$\psi K^+\pi^- p$, J/$\psi K^- \pi^- p$, J/$\psi K^- \pi^+ p$, and $J/\psi \phi (1020) p$ are reported. The data sample corresponds to an integrated luminosity of 3.0/fb in 7 and 8 TeV pp collisions acquired with the LHCb detector. Signals are not observed and upper limits are set on the product of the production cross section times branching fraction with respect to that of the $\Lambda_b$.
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PANDA experiment at FAIR. For the first time, high resolution gamma-spectroscopy of doubly strange Lambda Lambda-hypernuclei will be performed, thus complementing measurements of ground state decays of Lambda Lambda-hypernuclei at J-PARC or possible …
Study of e+e−→π0X(3872)γ and search for Zc(4020)0→X(3872)γ
The ALICE experiment at the CERN LHC
Journal of Instrumentation 3(08), S08002 (2008). doi:10.1088/1748-0221/3/08/S08002
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb–Pb collisions at sNN=2.76 TeV
The elliptic, v(2), triangular, v(3), and quadrangular, v(4), azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions, and (anti-)protons in Pb-Pb collisions at root S-NN = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range vertical bar eta vertical bar 8 GeV/c. The small p(T) dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to p(T) = 8 GeV/c. The magnitude of the (anti-)proton elliptic and triangular flo…
Simultaneous measurement of the muon neutrino charged-current cross section on oxygen and carbon without pions in the final state at T2K
Authors: K. Abe,56 N. Akhlaq,45 R. Akutsu,57 A. Ali,32 C. Alt,11 C. Andreopoulos,54,34 L. Anthony,21 M. Antonova,19 S. Aoki,31 A. Ariga,2 T. Arihara,59 Y. Asada,69 Y. Ashida,32 E. T. Atkin,21 Y. Awataguchi,59 S. Ban,32 M. Barbi,46 G. J. Barker,66 G. Barr,42 D. Barrow,42 M. Batkiewicz-Kwasniak,15 A. Beloshapkin,26 F. Bench,34 V. Berardi,22 L. Berns,58 S. Bhadra,70 S. Bienstock,53 S. Bolognesi,6 T. Bonus,68 B. Bourguille,18 S. B. Boyd,66 A. Bravar,13 D. Bravo Berguño,1 C. Bronner,56 S. Bron,13 A. Bubak,51 M. Buizza Avanzini ,10 T. Campbell,7 S. Cao,16 S. L. Cartwright,50 M. G. Catanesi,22 A. Cervera,19 D. Cherdack,17 N. Chikuma,55 G. Christodoulou,12 M. Cicerchia,24,† J. Coleman,34 G. Collazu…
Charged jet cross sections and properties in proton-proton collisions at $\sqrt{s}=7$ TeV
The differential charged jet cross sections, jet fragmentation distributions, and jet shapes are measured in minimum bias proton-proton collisions at centre-of-mass energy $\sqrt{s}=7$ TeV using the ALICE detector at the LHC. Jets are reconstructed from charged particle momenta in the mid-rapidity region using the sequential recombination $k_{\rm T}$ and anti-$k_{\rm T}$ as well as the SISCone jet finding algorithms with several resolution parameters in the range $R=0.2$ to $0.6$. Differential jet production cross sections measured with the three jet finders are in agreement in the transverse momentum ($p_{\rm T}$) interval $20<p_{\rm T}^{\rm jet,ch}<100$ GeV/$c$. They are also consistent w…
Two-pion Bose-Einstein correlations inppcollisions ats=900 GeV
We report on the measurement of two-pion correlation functions from pp collisions at root s = 900 GeV performed by the ALICE experiment at the Large Hadron Collider. Our analysis shows an increase of the Hanbury Brown-Twiss radius with increasing event multiplicity, in line with other measurements done in particle- and nuclear collisions. Conversely, the strong decrease of the radius with increasing transverse momentum, as observed at the Relativistic Heavy Ion Collider and at Tevatron, is not manifest in our data.
Column aerosol optical properties and aerosol radiative forcing during a serious haze-fog month over North China Plain in 2013 based on ground-based sunphotometer measurements
In January 2013, North China Plain experienced several serious haze events. Cimel sunphotometer measurements at seven sites over rural, suburban and urban regions of North China Plain from 1 to 30 January 2013 were used to further our understanding of spatial-temporal variation of aerosol optical parameters and aerosol radiative forcing (ARF). It was found that Aerosol Optical Depth at 500 nm (AOD500 nm) during non-pollution periods at all stations was lower than 0.30 and increased significantly to greater than 1.00 as pollution events developed. The Angstrom exponent (Alpha) was larger than 0.80 for all stations most of the time. AOD500 nm averages increased from north to south during both…
Charged kaon femtoscopic correlations inppcollisions ats=7 TeV
Correlations of two charged identical kaons (KchKch) are measured in pp collisions at root s = 7 TeV by the ALICE experiment at the Large Hadron Collider (LHC). One-dimensional (KKch)-K-ch correlation functions are constructed in three multiplicity and four transverse momentum ranges. The (KKch)-K-ch femtoscopic source parameters R and lambda are extracted. The (KKch)-K-ch correlations show a slight increase of femtoscopic radii with increasing multiplicity and a slight decrease of radii with increasing transverse momentum. These trends are similar to the ones observed for pi pi and K-s(0) K-s(0) correlations in pp and heavy-ion collisions. However at high multiplicities, there is an indica…
Measurement of pion, kaon and proton production in proton–proton collisions at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{s} = 7$$\end{document}s=7 TeV
The measurement of primary \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pi ^{\pm }$$\end{document}π±, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$K^{\pm }$$\end{document}K±, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrs…
Forward-central two-particle correlations in p–Pb collisions at sNN=5.02 TeV
Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 < |η| < 4.0) and associated particles in the cen
Pion Form Factor at BESIII
Abstract At BESIII, we measured the cross section of e + e − → π + π − in the energy range between 600 and 900 MeV/c2 with a 2.93 fb−1 data set taken at the center-of-mass energy 3.773 GeV. The initial state radiation technique is used, and the total systematic uncertainty is estimated to be 0.9%. The squared form factor | F π | 2 is extracted, and comparisons are made with results from both KLOE and BaBar. The two-pion contribution to the hadronic vacuum polarization contribution to ( g − 2 ) μ is calculated to be a μ π π , LO ( 600 − 900 MeV / c 2 ) = ( 368.2 ± 2.5 s t a t . ± 3.3 s y s t . ) ⋅ 10 − 10 .
Measurement of cross section for e+e−→Ξ0Ξ¯0 near threshold
Abstract Using e + e − collision data at ten center-of-mass energies between 2.644 and 3.080 GeV collected with the BESIII detector at BEPCII and corresponding to an integrated luminosity of about 500 pb−1, we measure the cross sections and effective form factors for the process e + e − → Ξ 0 Ξ ¯ 0 utilizing a single-tag method. A fit to the cross section of e + e − → Ξ 0 Ξ ¯ 0 with a pQCD-driven power function is performed, from which no significant resonance or threshold enhancement is observed. In addition, the ratio of cross sections for the processes e + e − → Ξ − Ξ ¯ + and Ξ 0 Ξ ¯ 0 is calculated using recent BESIII measurement and is found to be compatible with expectation from isosp…
Ds+ meson production at central rapidity in proton–proton collisions at s=7 TeV
The pt-differential inclusive production cross section of the prompt charm-strange meson D_s in the rapidity range |y| phi pi, with phi -> KK, and its charge conjugate, about 480 D_s mesons were counted, after selection cuts, in the transverse momentum range 2
Charged-Particle Multiplicity Density at Midrapidity in Central Pb-Pb Collisions atsNN=2.76 TeV
The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair root s(NN) = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 +/- 4(stat) +/- 76(syst), which corresponds to 8.3 +/- 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at root s(NN) = 0.2 TeV. This measurement provides the first experimental constraint for models…
βdecay of neutron-rich118Agand120Agisotopes
$\ensuremath{\beta}$ decays of on-line mass-separated neutron-rich ${}^{118}\mathrm{Ag}$ and ${}^{120}\mathrm{Ag}$ isotopes have been studied by using $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence spectroscopy. Extended decay schemes to the ${}^{118,120}\mathrm{Cd}$ daughter nuclei have been constructed. The three-phonon quintuplet in ${}^{118}\mathrm{Cd}$ is completed by including a new level at 2023.0 keV, which is tentatively assigned the spin and parity of ${2}_{4}^{+}.$ The intruder band in ${}^{118}\mathrm{Cd}$ is proposed up to the ${4}^{+}$ level at 2322.4 keV. The measured $\ensuremath{\beta}$-decay half…
Suppression of charged particle production at large transverse momentum in central Pb–Pb collisions at sNN=2.76 TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at root s(NN) = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in |eta| < 0.8 and 0.3 < p(T) < 20 GeV/c are compared to the expectation in pp collisions at the same root s(NN), scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor R-AA. The result indicates only weak medium effects (R-AA approximate to 0.7) in peripheral collisions. In cen…
Observation of $e^+e^-\toπ^0π^0ψ_2(3823)$
Using a data sample corresponding to an integrated luminosity of 11.3 $\rm fb^{-1}$ collected at center-of-mass energies from $4.23$ to $4.70$~GeV with the BESIII detector, we observe the process $e^+e^-\toπ^0π^0ψ_2(3823)$ for the first time with a statistical significance of $6.0σ$. The ratio of average cross sections for $e^+e^-\toπ^0π^0ψ_2(3823)$ over $π^+π^-ψ_2(3823)$ is determined to be $\mathcal{R}=\frac{σ[e^+e^-\toπ^0π^0ψ_2(3823)]}{σ[e^+e^-\toπ^+π^-ψ_2(3823)]}=0.57\pm 0.14\pm0.05$, which is consistent with expectations from isospin symmetry. Here and below, the first uncertainties are statistical and the second are systematic. The mass of the $ψ_2(3823)$ is measured to be $M[ψ_2(3823…
Determination of Spin-parity Quantum Numbers for the Narrow Structure Near the $p\bar{\Lambda}$ Threshold in $e^+e^-\to pK^-\bar{\Lambda}+c.c.$
A narrow structure in the $p\bar{\Lambda}$ system near the mass threshold, named as $X(2085)$, is observed in the process $e^+e^- \to p K^-\bar{\Lambda}$ with a statistical significance greater than $20\sigma$. Its spin and parity are determined for the first time to be $J^P=1^+$ in an amplitude analysis, with statistical significance greater than $5\sigma$ over other quantum numbers. The pole positions of $X(2085)$ are measured to be $M_{\rm pole}=(2086\pm4\pm6)$~MeV and $\Gamma_{\rm pole}=(56\pm5\pm16)$ MeV, where the first uncertainties are statistical and the second ones are systematic. The analysis is based on the study of the process $e^+e^-\to pK^-\bar{\Lambda}$ and uses the data sam…
Two-pion Bose–Einstein correlations in central Pb–Pb collisions at sNN=2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at root(NN)-N-S = 2.76 TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC. (C) 2010 CERN. Published by Elsevier B.V. All rights reserved.
Midrapidity Antiproton-to-Proton Ratio inppCollisons ats=0.9and 7 TeV Measured by the ALICE Experiment
The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at root s = 0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45 < p(t) < 1.05 GeV/c and rapidity vertical bar y vertical bar < 0.5. The ratio is measured to be R-vertical bar y vertical bar<0.5 = 0.957 +/- 0.006(stat) +/- 0.0014(syst) at 0.9 Tev and R-vertical bar y vertical bar<0.5 = 0.991 +/- 0.005 +/- 0.014(syst) at 7 TeV and it is independent of both rapidity and transverse momentum. The results are consistent with the conventional model of baryon-number transport and set stringent limits on a…
Search for the rare semi-leptonic decay J/ψ → D−e+ ν e + c.c.
Abstract Using 10.1 × 109J/ψ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy $$ \sqrt{s} $$ s = 3.097 GeV and collected with the BESIII detector, we present a search for the rare semi-leptonic decay J/ψ → D−e+νe + c.c. No excess of signal above background is observed, and an upper limit on the branching fraction ℬ(J/ψ → D−e+νe + c. c.) < 7.1 × 10−8 is obtained at 90% confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.
The β-decay approach for studying 12C
6 pags., 3 figs. -- 9th International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTERS'07) 3–7 September 2007, Stratford upon Avon, UK
Measurement of e+e−→γχc0,c1,c2 cross sections at center-of-mass energies between 3.77 and 4.60 GeV
Elliptic Flow of Charged Particles in Pb-Pb Collisions atsNN=2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at root s(NN) p = 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (vertical bar eta vertical bar < 0.8) and transverse momentum range 0.2 < p(t) < 5.0 GeV/c. The elliptic flow signal v(2), measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 +/- 0.002(stat) +/- 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v(2)(p(t)) reaches a maximum of 0.2 near p(t) = 3 GeV/c. Compared to RHIC Au-Au collisions at root s(NN) = 200 GeV, the elliptic f…
Observation of a cross-section enhancement near mass threshold in e + e - → Λ Λ
The process e(+)e(-) -> Lambda(Lambda) over bar is studied using data samples at root s = 2.2324, 2.400, 2.800 and 3.080 GeV collected with the BESIII detector operating at the BEPCII collider. The Born cross section is measured at root s = 2.2324 GeV, which is 1.0 MeVabove the Lambda(Lambda) over bar mass threshold, to be 305 +/- 45(-36)(+66) pb, where the first uncertainty is statistical and the second systematic. The cross section near threshold is larger than that expected from theory, which predicts the cross section to vanish at threshold. The Born cross sections at root s = 2.400, 2.800 and 3.080 GeV are measured and found to be consistent with previous experimental results, but with…
Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS
The observation of forward proton scattering in association with lepton pairs (eþe− þ p or μþμ− þ p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of ffiffiffi s p ¼ 13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee þ p (μμ þ p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced f…
Measurements of the branching fractions of ψ(3686)→Σ¯0Λ+c.c. and χcJ(J=0,1,2)→ΛΛ¯
Study of the $f_{0}(980)$ through the decay $D_{s}^{+} \to \pi^{+} \pi^{-} e^{+} \nu_{e}$
Using $e^+e^-$ collision data corresponding to an integrated luminosity of 7.33 ${\rm fb^{-1}}$ recorded by the BESIII detector at center-of-mass energies between 4.128 and 4.226 ${\rm GeV}$, we present an analysis of the decay $D_{s}^{+} \to f_{0}(980)e^{+}\nu_{e}$ with $f_{0}(980) \to \pi^{+}\pi^{-}$, where the $D_s^+$ is produced via the process $e^+e^- \to D_{s}^{*\pm}D_{s}^{\mp}$. We observe the $f_{0}(980)$ in the $\pi^+\pi^-$ system and the branching fraction of the decay $D_{s}^{+} \to f_{0}(980)e^{+}\nu_{e}$ with $f_0(980)\to\pi^+\pi^-$ is measured to be $(1.72 \pm 0.13_{\rm stat} \pm 0.10_{\rm syst}) \times10^{-3}$, where the uncertainties are statistical and systematic, respectiv…
Influences on the triple alpha process beyond the Hoyle state
7 pags., 3 figs. -- International Symposium on Nuclear Astrophysics - Nuclei in the Cosmos - IX, 25-30 June 2006, CERN
Measurement of the branching fraction of $D_s^+\to \tau^+ \nu_{\tau}$ via $\tau^+ \to \mu^+ \nu_{\mu}\bar{\nu_{\tau}}$
Utilizing $7.33~\mathrm{fb}^{-1}$ of $e^+e^-$ collision data taken at the center-of-mass energies of 4.128, 4.157, 4.178, 4.189, 4.199, 4.209, 4.219, and 4.226 GeV with the BESIII detector, the branching fraction of the leptonic decay $D_s^+\to\tau^+\nu_\tau$ via $\tau^+\to\mu^+\nu_\mu\bar \nu_\tau$ is measured to be $\mathcal{B}_{D_s^+\to\tau^+\nu_\tau}=(5.34\pm0.16_{\rm stat}\pm0.10_{\rm syst})\%$. Combining this branching fraction with the world averages of the measurements of the masses of $\tau^+$ and $D_s^+$ as well as the lifetime of $D_s^+$, we extract the product of the decay constant of $D_s^+$ and the $c\to s$ Cabibbo-Kobayashi-Maskawa matrix element to be $f_{D_s^+}|V_{cs}|=(246…
Measurement of the doubly Cabibbo-suppressed decay D+→K+π+π−π0 with semileptonic tags
Precision measurement of the mass difference between light nuclei and anti-nuclei
The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons and anti-deuterons, and $^{3}{\rm He}$ and $^3\overline{\rm He}…
Measurement of the branching fraction of leptonic decay Ds+ →τ+ντ via τ+ →π+π0 ν ¯ τ
Production of neutron-rich nuclei in fission induced by neutrons generated by the p + 13C reaction at 55 MeV
Cross-sections for the production of neutron-rich nuclei obtained by neutron-induced fission of natural uranium have been measured. The neutrons were generated by bombarding a 13C target with 55 MeV protons. The results, position of the maximum in the (Z, A)-plane, width and magnitude, are very comparable with those where the neutrons are generated by bombardment of natural 12C graphite with 50 MeV deuterons. Depending on the geometry of the converter/target assembly the isotope yields, however, are a factor of 2-3 lower due to less efficient production of neutrons per primary projectile, especially at small forward angles.
Search for the decay Ds+→a0(980)0e+νe
Using 6.32 fb−1 of electron-positron collision data recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we present the first search for the decay Ds+→a0(980)0e+νe, a0(980)0→π0η, which could proceed via a0(980)−f0(980) mixing. No significant signal is observed. An upper limit of 1.2×10−4 at the 90% confidence level is set on the product of the branching fractions of Ds+→a0(980)0e+νe and a0(980)0→π0η decays.
Neutron emission from electromagnetic dissociation of Pb nuclei at $\sqrt {s_{NN}} = 2.76$ TeV measured with the ALICE ZDC
The ALICE Zero Degree Calorimeter system (ZDC) is composed of two identical sets of calorimeters, placed at opposite sides with respect to the interaction point, 114 meters away from it, complemented by two small forward electromagnetic calorimeters (ZEM). Each set of detectors consists of a neutron (ZN) and a proton (ZP) ZDC. They are placed at zero degrees with respect to the LHC axis and allow to detect particles emitted close to beam direction, in particular neutrons and protons emerging from hadronic heavy-ion collisions (spectator nucleons) and those emitted from electromagnetic processes. For neutrons emitted by these two processes, the ZN calorimeters have nearly 100% acceptance. Du…
Observation of ψ(3686)→η′e+e−
Abstract Using a data sample of 448.1 × 10 6 ψ ( 3686 ) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay ψ ( 3686 ) → η ′ e + e − , with significances of 7.0σ and 6.3σ when reconstructing the η ′ meson via its decay modes η ′ → γ π + π − and η ′ → π + π − η ( η → γ γ ), respectively. The weighted average branching fraction is determined to be B ( ψ ( 3686 ) → η ′ e + e − ) = ( 1.90 ± 0.25 ± 0.11 ) × 10 − 6 , where the first uncertainty is statistical and the second systematic.
Beauty production in pp collisions at s=2.76 TeV measured via semi-electronic decays
The ALICE Collaboration at the LHC reports measurement of the inclusive production cross section of electrons from semi-leptonic decays of beauty hadrons with rapidity |y|<0.8 and transverse momentum 1<pT<10 GeV/c, in pp collisions at s=2.76 TeV. Electrons not originating from semi-electronic decay of beauty hadrons are suppressed using the impact parameter of the corresponding tracks. The production cross section of beauty decay electrons is compared to the result obtained with an alternative method which uses the distribution of the azimuthal angle between heavy-flavour decay electrons and charged hadrons. Perturbative QCD predictions agree with the measured cross section within the exper…
Clarification of the Three-Body Decay ofC12(12.71 MeV)
Using $\ensuremath{\beta}$ decays of a clean source of $^{12}\mathrm{N}$ produced at the IGISOL facility, we have measured the breakup of the $^{12}\mathrm{C}$ (12.71 MeV) state into three $\ensuremath{\alpha}$ particles with a segmented particle detector setup. The high quality of the data permits solving the question of the breakup mechanism of the 12.71 MeV state, a longstanding problem in few-body nuclear physics. Among existing models, a modified sequential model fits the data best, but systematic deviations indicate that a three-body description is needed.
Precise branching ratios to unbound 12C states from 12N and 12B β-decays
6 pages, 2 tables, 4 figures.--PACS nrs.: 21.45.-v; 23.40.-s; 27.20.+n; 21.60.De.--Printed version published Aug 3, 2009
Measurement of the absolute branching fraction of the singly Cabibbo suppressed decay Λc+ →pη′
Physical review / D 106(7), 072002 (2022). doi:10.1103/PhysRevD.106.072002
New Features in the Electromagnetic Structure of the Neutron
Here we present new results for the Born cross section and the effective form factor of the neutron at the center-of-mass energies ${\bf \sqrt{s}}$ between 2.0 and 3.08 GeV, using 18 data sets corresponding to an integrated luminosity of 647.9 pb${\bf ^{-1}}$ from e${\bf ^+}$e${\bf ^-}$ annihilation reactions collected at the BESIII experiment. The process $e^{+}e^{-}\to n\bar{n}$ is analyzed with three individual categories to improve the efficiency of $n\bar{n}$ reconstruction. The cross section of $e^{+}e^{-}\to n\bar{n}$ is measured at 18 c.m. energies where the best precision is 8.1\% at $\sqrt{s}=2.396$ GeV. The corresponding effective form factors are extracted under the assumption $…
Status of HIGISOL a new version equipped with SPIG and electric field guidance
A new HIGISOL chamber devoted to the study of short-lived products from heavy-ion-induced fusion-evaporation reactions is proposed. It enables, via the extraction of ions by means of a SPIG (SextuPole rf Ion Guide), to improve the mass resolving power by a factor 2.5 compared to the previous system using a skimmer-ring assembly. The gas cell was also equiped with an electric field for faster transportation of recoiling ions to the nozzle where they are ejected with the gas jet. The first results obtained both with a radioactive α-source and cyclotron beam will be reported.
Five insights from the Global Burden of Disease Study 2019
The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD …
Measurement of photon?jet transverse momentum correlations in 5.02 TeV Pb + Pb and pp collisions with ATLAS
Jets created in association with a photon can be used as a calibrated probe to study energy loss in the medium created in nuclear collisions. Measurements of the transverse momentum balance between isolated photons and inclusive jets are presented using integrated luminosities of 0.49 nb−1 of Pb + Pb collision data at TeV and 25 pb−1 of pp collision data at TeV recorded with the ATLAS detector at the LHC. Photons with transverse momentum GeV and are paired with all jets in the event that have GeV and pseudorapidity . The transverse momentum balance given by the jet-to-photon ratio, , is measured for pairs with azimuthal opening angle . Distributions of the per-photon jet yield as a function…
Neutral pion and η meson production in proton–proton collisions at s=0.9 TeV and s=7 TeV
The first measurements of the invariant differential cross sections of inclusive pi(0) and eta meson production at mid-rapidity in proton-proton collisions root s = 0.9 TeV and root s = 7 TeV are reported. The pi(0) measurement covers the ranges 0.4 < p(T) < 7 GeV/c and 0.3 < p(T) < 25 GeV/c for these two energies, respectively. The production of eta mesons was measured at root s = 7 TeV in the range 0.4 < p(T) < 15 GeV/c. Next-to-Leading Order perturbative QCD calculations, which are consistent with the pi(0) spectrum at root s = 0.9 TeV, overestimate those of pi(0) and eta mesons at root s = 7 TeV, but agree with the measured eta/pi(0) ratio at root s = 7 TeV. (C) 2012 CERN. Published by …
Measurements of Differential Cross Sections of Inclusive $\pi^0$ and $K^0_S$ Production in $e^{+}e^{-}$ Annihilation at Energies from 2.2324 to 3.6710 GeV
Based on electron positron collision data collected with the BESIII detector operating at the BEPCII storage rings, the differential cross sections of inclusive $\pi^0$ and $K^0_S$ production as a function of hadron momentum, normalized by the total cross section of the $e^{+}e^{-} \to$ hadrons process, are measured at six center-of-mass energies from 2.2324 to 3.6710 GeV. Our results with a relative hadron energy coverage from 0.1 to 0.9 significantly deviate from several theoretical calculations based on existing fragmentation functions, especially at lower energies.
Measurement of the $e^{+}e^{-}\rightarrow\Lambda\bar{\Lambda}$ cross section from threshold to 3.00 GeV using events with initial-state radiation
Using initial-state radiation events from a total integrated luminosity of 11.957 fb$^{-1}$ of $e^+e^-$ collision data collected at center-of-mass energies between 3.773 and 4.258 GeV with the BESIII detector at BEPCII, the cross section for the process $e^{+}e^{-}\rightarrow\Lambda\bar{\Lambda}$ is measured in 16 $\Lambda\bar{\Lambda}$ invariant mass intervals from the production threshold up to 3.00 GeV$/c^{2}$. The results are consistent with previous results from BaBar and BESIII, but with better precision and with narrower $\Lambda\bar{\Lambda}$ invariant mass intervals than BaBar.
Measurement of the branching fraction and decay asymmetry of $Λ\to nγ$
The radiative hyperon decay $Λ\to nγ$ is studied using $(10087\pm44)\times 10^6$ $J/ψ$ events collected with the BESIII detector operating at BEPCII. The absolute branching fraction of the decay $Λ\to nγ$ is determined with a significance of 5.6$σ$ to be $[0.832\pm0.038(\rm stat.)\pm0.054(\rm syst.)]\times10^{-3}$, which lies significantly below the current PDG value. By analyzing the joint angular distribution of the decay products, the first determination of the decay asymmetry $α_γ$ is reported with a value of $-0.16\pm0.10(\rm stat.)\pm0.05(\rm syst.)$.
β-decay ofO13
The beta decay of O-13 has been studied at the IGISOL facility of the Jyvaskyla accelerator centre (Finland). By developing a low-energy isotope-separated beam of O-13 and using a modern segmented charged-particle detector array an improved measurement of the delayed proton spectrum was possible. Protons with energy up to more than 12 MeV are measured and the corresponding log(ft) values extracted. A revised decay scheme is constructed. The connection to molecular states and the shell model is discussed.
Observation of the Singly Cabibbo Suppressed Decay Λc+→nπ+
Physical review letters 128(14), 142001 (2022). doi:10.1103/PhysRevLett.128.142001
Transverse Momentum Distribution and Nuclear Modification Factor of Charged Particles inp+PbCollisions atsNN=5.02 TeV
The transverse momentum (pT) distribution of primary charged particles is measured in minimum bias (non-single-diffractive) p + Pb collisions at root(NN)-N-s = 5.02 TeV with the ALICE detector at the LHC. The pT spectra measured near central rapidity in the range 0.5< p(T) < 20 GeV/c exhibit a weak pseudorapidity dependence. The nuclear modification factor R-pPb is consistent with unity for p(T) above 2 GeV/c. This measurement indicates that the strong suppression of hadron production at high p(T) observed in Pb + Pb collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical calculations. DOI: 10.1103/PhysRevLett.110.082302
Setting the future of digital and social media marketing research: Perspectives and research propositions
in press The use of the internet and social media have changed consumer behavior and the ways in which companies conduct their business. Social and digital marketing offers significant opportunities to organizations through lower costs, improved brand awareness and increased sales. However, significant challenges exist from negative electronic word-of-mouth as well as intrusive and irritating online brand presence. This article brings together the collective insight from several leading experts on issues relating to digital and social media marketing. The experts' perspectives offer a detailed narrative on key aspects of this important topic as well as perspectives on more specific issues i…
Subnational mapping of HIV incidence and mortality among individuals aged 15-49 years in sub-Saharan Africa, 2000-18: a modelling study
Background. High-resolution estimates of HIV burden across space and time provide an important tool for tracking and monitoring the progress of prevention and control efforts and assist with improving the precision and efficiency of targeting efforts. We aimed to assess HIV incidence and HIV mortality for all second-level administrative units across sub-Saharan Africa. Methods. In this modelling study, we developed a framework that used the geographically specific HIV prevalence data collected in seroprevalence surveys and antenatal care clinics to train a model that estimates HIV incidence and mortality among individuals aged 15–49 years. We used a model-based geostatistical framework to e…
Search for new decay modes of the $\psi_2(3823)$ and the process $e^+e^-\rightarrow\pi^0\pi^0\psi_2(3823)$
The decays $\psi_2(3823)\rightarrow\gamma\chi_{c0,1,2}, \pi^+\pi^-J/\psi, \pi^0\pi^0J/\psi, \eta J/\psi$, and $\pi^0J/\psi$ are searched for using the reaction $e^+e^-\rightarrow\pi^+\pi^-\psi_2(3823)$ in a 19 fb$^{-1}$ data sample collected at center-of-mass energies between 4.1 and 4.7 GeV with the BESIII detector. The process $\psi_2(3823)\rightarrow\gamma\chi_{c1}$ is observed in a 9 fb$^{-1}$ data sample in the center-of-mass energy range 4.3 to 4.7 GeV, which confirms a previous observation but with a higher significance of $11.8\sigma$, and evidence for $\psi_2(3823)\rightarrow\gamma\chi_{c2}$ is found with a significance of $3.2\sigma$ for the first time. The branching-fraction rati…
Measurement of quarkonium production at forward rapidity in \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathbf {pp}$$\end{document}pp collisions at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathbf {\sqrt{s}=7}~$$\end{document}s=7TeV
The inclusive production cross sections at forward rapidity of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathrm{J}/\psi }$$\end{document}J/ψ, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\psi (\mathrm{2S})}$$\end{document}ψ(2S), \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} …
Search for hyperon $ΔS=ΔQ$ violating decay $Ξ^{0}\toΣ^{-}e^{+}ν_{e}$
Using a data sample of $(1.0087\pm0.0044)\times10^{10}$ $J/ψ$ decay events collected with the BESIII detector at the center-of-mass energy of $\sqrt{s}=3.097$ GeV, we present a search for the hyperon semileptonic decay $Ξ^{0}\toΣ^{-}e^{+}ν_{e}$ which violates the $ΔS=ΔQ$ rule. No significant signal is observed, and the upper limit on the branching fraction $\mathcal{B}(Ξ^{0}\toΣ^{-}e^{+}ν_{e})$ is determined to be $1.6\times10^{-4}$ at the 90% confidence level. This result improves the previous upper limit result by about one order of magnitude.
Measurement of the absolute branching fraction of the inclusive semileptonic $\Lambda_c^+$ decay
Physical review letters 121(25), 251801 (2018). doi:10.1103/PhysRevLett.121.251801
Observation of $D^0\to K_1(1270)^- e^+\nu_e$
Using 2.93 fb$^{-1}$ of $e^+e^-$ collision data taken with the BESIII detector at a center-of-mass energy of 3.773 $\rm \,GeV$, the observation of the $D^0\to K_1(1270)^- e^+\nu_e$ semileptonic decay is presented. The statistical significance of the decay $D^0\to K_1(1270)^- e^+\nu_e$ is greater than $10\sigma$. The branching fraction of $D^0\to K_1(1270)^- e^+\nu_e$ is measured to be $(1.09\pm0.13^{+0.09}_{-0.16} \pm 0.12)\times10^{-3}$. Here, the first uncertainty is statistical, the second is systematic, and the third originates from the assumed branching fraction of $K_1(1270)^- \rightarrow K^-\pi^+\pi^-$. The fraction of longitudinal polarization in $D^0\to K_1(1270)^- e^+\nu_e$ is det…
Inclusive J/ψ production in pp collisions at s=2.76 TeV
The ALICE Collaboration has measured inclusive J/psi production in pp collisions at a center of mass energy sqrt(s)=2.76 TeV at the LHC. The results presented in this Letter refer to the rapidity ranges |y|<0.9 and 2.5
Performance of the ALICE VZERO system
ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton-proton, proton--nucleus and nucleus-nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central role in ALICE. In addition to its core function as a trigger, the VZERO system is used to monitor LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such as luminosity, particle multiplicity, centrality and event plane direction in nucleus-nucleus collisions. After describing the VZERO system, this publication presents its performance o…
Observation of a Near-Threshold Structure in the K + Recoil-Mass Spectra in e + e − → K + ( D s − D * 0 + D s * − D 0 )
Isomeric state of 80Y and its role in the rp-process
The HIGISOL facility has been used to investigate carefully the isomeric transition 228.5 keV in 80Y. We have measured the electron internal conversion coefficient for this transition αK = 0.50 ± 0.07 which gives the value for half-life of “bare” isomeric state T 1/2 = 6.8 ± 0.5 s. The isomeric state should play an important role in the rp-process calculations.
Measurement of the Cross Section for Electromagnetic Dissociation with Neutron Emission in Pb-Pb Collisions atsNN=2.76 TeV
The first measurement of neutron emission in electromagnetic dissociation of Pb-208 nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at root s(NN) = 2.76 TeV with neutron emission are sigma(singleEMD) = 187.4 +/- 0.2(stat)(-11.2)(+13.2) (syst) b and sigma(mutualEMD) = 5. 7 +/- 0.1(stat) +/- 0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model. DOI: 10.1103/PhysRevLett.109.252302
Search for the decay $D_s^+\to a_0(980)^0e^+\nu_e$
Using 6.32 fb$^{-1}$ of electron-positron collision data recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, we present the first search for the decay $D_s^+\to a_0(980)^0 e^+\nu_e,\,a_0(980)^0\rightarrow \pi^0\eta$, which could proceed via $a_0(980)$-$f_0(980)$ mixing. No significant signal is observed. An upper limit of $1.2 \times 10^{-4}$ at the $90\%$ confidence level is set on the product of the branching fractions of $D_{s}^{+}\to a_0(980)^0 e^+\nu_e$ and $a_0(980)^0\rightarrow \pi^0\eta$ decays.
The ALICE Collaboration
The production of mesons containing strange quarks (KS, φ) and both singly and doubly strange baryons ( , , and − + +) are measured at mid-rapidity in pp collisions at √ s = 0.9 TeV with the ALICE experiment at the LHC. The results are obtained from the analysis of about 250 k minimum bias events recorded in 2009. Measurements of yields (dN/dy) and transverse momentum spectra at mid-rapidity for inelastic pp collisions are presented. For mesons, we report yields (〈dN/dy〉) of 0.184 ± 0.002(stat.) ± 0.006(syst.) for KS and 0.021 ± 0.004(stat.) ± 0.003(syst.) for φ. For baryons, we find 〈dN/dy〉 = 0.048 ± 0.001(stat.) ± 0.004(syst.) for , 0.047 ± 0.002(stat.) ± 0.005(syst.) for and 0.0101 ± 0.0…
Observation of an Isoscalar Resonance with Exotic J P C = 1 − + Quantum Numbers in J / ψ → γ η η ′
Coherent ψ(2S) photo-production in ultra-peripheral Pb Pb collisions at sNN=2.76 TeV
We have performed the first measurement of the coherent ψ(2S) photo-production cross section in ultraperipheral Pb–Pb collisions at the LHC. This charmonium excited state is reconstructed via the ψ(2S) → l +l − and ψ(2S) → J/ψπ+π− decays, where the J/ψ decays into two leptons. The analysis is based on an event sample corresponding to an integrated luminosity of about 22 μb−1. The cross section for coherent ψ(2S) production in the rapidity interval −0.9 < y < 0.9 is dσcoh ψ(2S)/dy = 0.83±0.19 stat+syst mb. The ψ(2S) to J/ψ coherent cross section ratio is 0.34+0.08 −0.07(stat + syst). The obtained results are compared to predictions from theoretical models.
Breakup channels forC12triple-αcontinuum states
The triple-alpha-particle breakup of states in the triple-alpha continuum of C-12 has been investigated by way of coincident detection of all three alpha particles of the breakup. The states have been fed in the beta decay of N-12 and B-12, and the alpha particles measured using a setup that covers all of the triple-alpha phase space. Contributions from the breakup through the Be-8(0(+)) ground state as well as other channels-interpreted as breakup through excited energies in Be-8-have been identified. Spins and parities of C-12 triple-alpha continuum states are deduced from the measured phase-space distributions for breakup through Be-8 above the ground state by comparison to a fully symme…
Suppression of ϒ(1S) at forward rapidity in Pb–Pb collisions at sNN=2.76 TeV
We report on the measurement of the inclusive Υ (1S) production in Pb–Pb collisions at √sNN = 2.76 TeV carried out at forward rapidity (2.5 < y < 4) and down to zero transverse momentum using its μ+μ− decay channel with the ALICE detector at the Large Hadron Collider. A strong suppression of the inclusive Υ (1S) yield is observed with respect to pp collisions scaled by the number of independent nucleon– nucleon collisions. The nuclear modification factor, for events in the 0–90% centrality range, amounts to 0.30 ± 0.05(stat) ± 0.04(syst). The observed Υ (1S) suppression tends to increase with the centrality of the collision and seems more pronounced than in corresponding mid-rapidity measur…
Higher Harmonic Anisotropic Flow Measurements of Charged Particles in Pb-Pb Collisions atsNN=2.76 TeV
We report on the first measurement of the triangular nu(3), quadrangular nu(4), and pentagonal nu(5) charged particle flow in Pb-Pb collisions at root s(NN) = 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow nu(2) and nu(3) have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained fr…
Study of the decay D+→K*(892)+KS0 in D+→K+KS0π0
Spatial distribution of aerosol microphysical and optical properties and direct radiative effect from the China Aerosol Remote Sensing Network
Multi-year observations of aerosol microphysical and optical properties, obtained through ground-based remote sensing at 50 China Aerosol Remote Sensing Network (CARSNET) sites, were used to characterize the aerosol climatology for representative remote, rural, and urban areas over China to assess effects on climate. The annual mean effective radii for total particles (ReffT) decreased from north to south and from rural to urban sites, and high total particle volumes were found at the urban sites. The aerosol optical depth at 440 nm (AOD440 nm) increased from remote and rural sites (0.12) to urban sites (0.79), and the extinction Ångström exponent (EAE440–870 nm) increased fro…
Centrality determination of Pb-Pb collisions atsNN=2.76TeV with ALICE
This publication describes the methods used to measure the centrality of inelastic Pb-Pb collisions at a center-of-mass energy of 2.76 TeV per colliding nucleon pair with ALICE. The centrality is a key parameter in the study of the properties of QCD matter at extreme temperature and energy density, because it is directly related to the initial overlap region of the colliding nuclei. Geometrical properties of the collision, such as the number of participating nucleons and the number of binary nucleon-nucleon collisions, are deduced from a Glauber model with a sharp impact parameter selection and shown to be consistent with those extracted from the data. The centrality determination provides …
Search for new decay modes of the ψ2(3823) and the process e+e−→π0π0ψ2(3823)
Measurement of theDs+→ℓ+νℓbranching fractions and the decay constantfDs+
Using 482 pb(-1) of e(+) e(-) collision data collected at a center-of-mass energy of root s = 4.009 GeV with the BESIII detector, we measure the branching fractions of the decays D-s(+) -> u(+)v(u) and D-s(+) -> tau(+)v(tau). By constraining the ratio of decay rates of Ds(+) to tau(+)v(u) and to u(+)v(u) to the Standard Model prediction, the branching fractions are determined to be B(D-s(+) -> u(+)v(u) = (0.495 +/- 0.067 +/- 0.026)% and B(D-s(+) -> tau(+)v(tau) = (4.83 +/- 0.65 +/- 0.26)% Using these branching fractions, we obtain a value for the decay constant f(Ds+) of (241.0 +/- 16.3 +/- 6.5) MeV, where the first error is statistical and the second systematic.
Measurement of jet suppression in central Pb–Pb collisions at sNN=2.76 TeV
The transverse momentum(p(T)) spectrum and nuclear modification factor (R-AA) of reconstructed jets in 0-10% and 10-30% central Pb-Pb collisions at root s(NN) = 2.76 TeV were measured. Jets were reconstructed using the anti-k(T) jet algorithm with a resolution parameter of R = 0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet p(T) spectra are reported in the pseudorapidity interval of \eta(jet)\ 5 GeV/c to suppress jets constructed from the combinatorial background in Pb-Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb-Pb collisions had a negligible effect on the R-A…
Observation ofe+e−→γX(3872)at BESIII
Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of root s = 4.23, 4.26, and 4.36 GeV, we observe e(+)e(-) -> pi(0)pi(0)h(c) for the first time. The Born cross sections are measured and found to be about half of those of e(+)e(-) -> pi(+)pi(-)h(c) within less than 2 sigma. In the pi(0)h(c) mass spectrum, a structure at 4.02 GeV/c(2) is found. It is most likely to be the neutral isospin partner of the Z(c)(4020)(+/-) observed in the process of e(+)e(-) -> pi(+)pi(-)h(c) being found. A fit to the pi(0)h(c) invariant mass spectrum, with the width of the Z(c)(4020)(0) fixed to that of its charged isospin partner and pos…
Search for the semi-leptonic decays $\Lambda_c^+ \to \Lambda \pi^+ \pi^- e^+ \nu_e$ and $\Lambda_c^+ \to p K_S^0 \pi^- e^+ \nu_e$
We search for the semi-leptonic decays $\Lambda_c^+ \to \Lambda \pi^+ \pi^- e^+ \nu_e$ and $\Lambda_c^+ \to p K_S^0 \pi^- e^+ \nu_e$ in a sample of 4.5 $\mathrm{fb}^{-1}$ of $e^{+}e^{-}$ annihilation data collected in the center-of-mass energy region between 4.600 GeV and 4.699 GeV by the BESIII detector at the BEPCII. No significant signals are observed, and the upper limits on the decay branching fractions are set to be $\mathcal{B}(\Lambda_c^+ \to \Lambda \pi^+ \pi^- e^+ \nu_e)<3.9\times10^{-4}$ and $\mathcal{B}(\Lambda_c^+ \to p K_S^0 \pi^- e^+ \nu_e)<3.3\times10^{-4}$ at the 90% confidence level, respectively.
Study of the decay D s + → K S 0 K S 0 π + and observation of an isovector partner to f 0 ( 1710 )
Femtoscopy ofppcollisions ats=0.9and 7 TeV at the LHC with two-pion Bose-Einstein correlations
We report on the high statistics two-pion correlation functions from pp collisions at root s = 0.9 TeV and root s = 7 TeV, measured by the ALICE experiment at the Large Hadron Collider. The correlation functions as well as the extracted source radii scale with event multiplicity and pair momentum. When analyzed in the same multiplicity and pair transverse momentum range, the correlation is similar at the two collision energies. A three-dimensional femtoscopic analysis shows an increase of the emission zone with increasing event multiplicity as well as decreasing homogeneity lengths with increasing transverse momentum. The latter trend gets more pronounced as multiplicity increases. This sug…
Observation of the decay $\chi_{cJ} \to \Omega^- \bar{\Omega}^+$
Using an $e^+e^-$ collision data sample of $(27.08 \pm 0.14) \times 10^{8}$ $\psi(3686)$ events collected by the BESIII detector, we report the first observation of $\chi_{cJ} \to \Omega^- \bar{\Omega}^+$ ($J=0,\,1,\,2$) decays with significances of $5.6\sigma$, $6.4\sigma$, and $18\sigma$, respectively, where the $\chi_{cJ}$ mesons are produced in the radiative $\psi(3686)$ decays. The branching fractions are determined to be $\mathcal{B}(\chi_{c0} \to \Omega^- \bar{\Omega}^+) = (3.51 \pm 0.54 \pm 0.29) \times 10^{-5}$, $\mathcal{B}(\chi_{c1} \to \Omega^- \bar{\Omega}^+) = (1.49 \pm 0.23 \pm 0.10) \times 10^{-5}$, and $\mathcal{B}(\chi_{c2} \to \Omega^- \bar{\Omega}^+) = (4.52 \pm 0.24 \pm…
Measurements of Born cross sections of e+e−→Ds*+DsJ−+c.c.
Search for the decay $D^{0} \to π^{0} ν\barν$
We present the first experimental search for the rare charm decay $D^{0} \to π^{0} ν\barν$. It is based on an $e^+e^-$ collision sample consisting of $10.6\times10^{6}$ pairs of $D^0\bar{D}^0$ mesons collected by the BESIII detector at $\sqrt{s}$=3.773 GeV, corresponding to an integrated luminosity of 2.93~fb$^{-1}$. A data-driven method is used to ensure the reliability of the background modeling. No significant $D^{0} \to π^{0} ν\barν$ signal is observed in data and an upper limit of the branching fraction is set to be $2.1\times 10^{-4}$ at the 90$\%$ confidence level. This is the first experimental constraint on charmed-hadron decays into dineutrino final states.
Search for the decay D0 → π0ν¯v
We present the first experimental search for the rare charm decay D0→π0νν¯. It is based on an e+e− collision sample consisting of 10.6×106 pairs of D0D¯0 mesons collected by the BESIII detector at s=3.773 GeV, corresponding to an integrated luminosity of 2.93 fb−1. A data-driven method is used to ensure the reliability of the background modeling. No significant D0→π0νν¯ signal is observed in data and an upper limit of the branching fraction is set to be 2.1×10−4 at the 90% confidence level. This is the first experimental constraint on charmed-hadron decays into dineutrino final states.
Study of $e^{+}e^{-} \to D^{+} D^{-} \pi^{+} \pi^{-} $ at center-of-mass energies from 4.36 to 4.60 GeV
We report a study of the $e^{+}e^{-} \to D^{+} D^{-} \pi^{+} \pi^{-}$ process using $e^{+}e^{-}$ collision data samples with an integrated luminosity of $2.5\,\rm{fb}^{-1}$ at center-of-mass energies from 4.36 to $4.60 \rm{GeV}$, collected with the BESIII detector at the BEPCII storage ring. The $D_{1}(2420)^+$ is observed in the $D^{+} \pi^{+} \pi^{-}$ mass spectrum. The mass and width of the $D_{1}(2420)^+$ are measured to be $(2427.2\pm 1.0_{\rm stat.}\pm 1.2_{\rm syst.}) \rm{MeV}/c^2$ and $(23.2\pm 2.3_{\rm stat.} \pm2.3_{\rm syst.}) \rm{MeV}$, respectively. The first errors are statistical and the second ones are systematic. In addition, the Born cross sections of the $e^{+}e^{-} \to D…
Centrality dependence ofπ,K, andpproduction in Pb-Pb collisions atsNN=2.76TeV
In this paper measurements are presented of pi(+/-), K-+/-, p, and (p) over bar production at midrapidity (vertical bar y vertical bar < 0.5), in Pb-Pb collisions at root s(NN) = 2.76 TeV as a function of centrality. The measurement covers the transverse-momentum (p(T)) range from 100, 200, and 300 MeV/c up to 3, 3, and 4.6 GeV/c for pi, K, and p, respectively. The measured p(T) distributions and yields are compared to expectations based on hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In peripheral collisions, the p(T) distributions are not…
Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions atsNN=2.76TeV
We report on results obtained with the event-shape engineering technique applied to Pb-Pb collisions at √sNN=2.76 TeV. By selecting events in the same centrality interval, but with very different average flow, different initial-state conditions can be studied. We find the effect of the event-shape selection on the elliptic flow coefficient v2 to be almost independent of transverse momentum pT, which is as expected if this effect is attributable to fluctuations in the initial geometry of the system. Charged-hadron, -pion, -kaon, and -proton transverse momentum distributions are found to be harder in events with higher-than-average elliptic flow, indicating an interplay between radial and ell…
Production of inclusive ϒ(1S) and ϒ(2S) in p–Pb collisions at sNN=5.02 TeV
We report on the production of inclusive Y{hooktop}(1S) and Y{hooktop}(2S) in p-Pb collisions at √sNN=5.02 TeV at the LHC. The measurement is performed with the ALICE detector at backward (-4.46<ycms<-2.96) and forward (2.03<ycms<3.53) rapidity down to zero transverse momentum. The production cross sections of the Y{hooktop}(1S) and Y{hooktop}(2S) are presented, as well as the nuclear modification factor and the ratio of the forward to backward yields of Y{hooktop}(1S). A suppression of the inclusive Y{hooktop}(1S) yield in p-Pb collisions with respect to the yield from pp collisions scaled by the number of binary nucleon-nucleon collisions is observed at forward rapidity but not at backwar…
Energy dependence of the transverse momentum distributions of charged particles in pp collisions measured by ALICE
Differential cross sections of charged particles in inelastic pp collisions as a function of $p_{\rm T}$ have been measured at $\sqrt{s}=$ 0.9, 2.76 and 7 TeV at the LHC. The $p_{\rm T}$ spectra are compared to NLO-pQCD calculations. Though the differential cross section for an individual $\sqrt{s}$ cannot be described by NLO-pQCD, the relative increase of cross section with $\sqrt{s}$ is in agreement with NLO-pQCD. Based on these measurements and observations, procedures are discussed to construct pp reference spectra at $\sqrt{s} =$ 2.76 and 5.02 TeV up to $p_{\rm T}$ = 50 GeV/$c$ as required for the calculation of the nuclear modification factor in nucleus-nucleus and proton-nucleus coll…
Measurement of visible cross sections in proton-lead collisions at √sNN= 5.02 TeV in van der Meer scans with the ALICE detector
In 2013, the Large Hadron Collider provided proton-lead and lead-proton collisions at the center-of-mass energy per nucleon pair $\sqrt{s_{\rm{NN}}}=5.02$ TeV. Van der Meer scans were performed for both configurations of colliding beams, and the cross section was measured for two reference processes, based on particle detection by the T0 and V0 detectors, with pseudo-rapidity coverage $4.6<\eta< 4.9$, $-3.3<\eta<-3.0$ and $2.8<\eta< 5.1$, $-3.7<\eta<-1.7$, respectively. Given the asymmetric detector acceptance, the cross section was measured separately for the two configurations. The measured visible cross sections are used to calculate the integrated luminosity of the proton-lead and lead-…
Centrality Dependence of the Charged-Particle Multiplicity Density at Midrapidity in Pb-Pb Collisions atsNN=2.76 TeV
The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at root s(NN) = 2: 76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
Assessment of the worldwide burden of critical illness: The Intensive Care Over Nations (ICON) audit
Item does not contain fulltext BACKGROUND: Global epidemiological data regarding outcomes for patients in intensive care units (ICUs) are scarce, but are important in understanding the worldwide burden of critical illness. We, therefore, did an international audit of ICU patients worldwide and assessed variations between hospitals and countries in terms of ICU mortality. METHODS: 730 participating centres in 84 countries prospectively collected data on all adult (>16 years) patients admitted to their ICU between May 8 and May 18, 2012, except those admitted for fewer than 24 h for routine postoperative monitoring. Participation was voluntary. Data were collected daily for a maximum of 28 da…
K*(892)0 and ϕ(1020) meson production at high transverse momentum in pp and Pb-Pb collisions at sNN=2.76 TeV
The yields of the K*(892)(0) and phi(1020) resonances are measured in Pb-Pb collisions at root s(NN) = 2.76 TeV through their hadronic decays using the ALICE detector. The measurements are performed in multiple centrality intervals at mid-rapidity (vertical bar y vertical bar <0.5) in the transverse-momentum ranges 0.3 <p(T) <5 GeV/c for the K*(892)(0) and 0.5 <p(T) <5 GeV/c for the phi(1020). The yields of K*(892)(0) are suppressed in central Pb-Pb collisions with respect to pp and peripheral Pb-Pb collisions (perhaps due to rescattering of its decay products in the hadronic medium), while the longer-lived phi(1020) meson is not suppressed. These particles are also used as probes to study …
Measurements of cross section of e+e−→pp¯π0 at center-of-mass energies between 4.008 and 4.600 GeV
Based on e(+)e(-) annihilation data samples collected with the BESIII detector at the BEPCII collider at 13 center-of-mass energies from 4.008 to 4.600 GeV, measurements of the Born cross section o ...
Observation of an Isoscalar Resonance with Exotic $J^{P C} = 1^{− +}$ Quantum Numbers in $J / ψ → γ η η ′$
Physical review letters 129(19), 192002 (2022). doi:10.1103/PhysRevLett.129.192002
Measurements of the branching fractions for D+→KS0KS0K+, KS0KS0π+ and D0→KS0KS0, KS0KS0KS0
Abstract By analyzing 2.93 fb − 1 of data taken at the ψ ( 3770 ) resonance peak with the BESIII detector, we measure the branching fractions for the hadronic decays D + → K S 0 K S 0 K + , D + → K S 0 K S 0 π + , D 0 → K S 0 K S 0 and D 0 → K S 0 K S 0 K S 0 . They are determined to be B ( D + → K S 0 K S 0 K + ) = ( 2.54 ± 0.05 s t a t . ± 0.12 s y s . ) × 10 − 3 , B ( D + → K S 0 K S 0 π + ) = ( 2.70 ± 0.05 s t a t . ± 0.12 s y s . ) × 10 − 3 , B ( D 0 → K S 0 K S 0 ) = ( 1.67 ± 0.11 s t a t . ± 0.11 s y s . ) × 10 − 4 and B ( D 0 → K S 0 K S 0 K S 0 ) = ( 7.21 ± 0.33 s t a t . ± 0.44 s y s . ) × 10 − 4 , where the second one is measured for the first time and the others are measured wit…
Measurement of the phase between strong and electromagnetic amplitudes of J/ψ decays
Kolcu, Onur Buğra (Arel Author)
Measurement of the Cross Section for e+e−→Ξ−Ξ¯+ and Observation of an Excited Ξ Baryon
Using a total of 11.0 fb−1 of e+e− collision data with center-of-mass energies between 4.009 and 4.6 GeV and collected with the BESIII detector at BEPCII, we measure fifteen exclusive cross sections and effective form factors for the process e+e−→Ξ−Ξ¯+ by means of a single baryon-tag method. After performing a fit to the dressed cross section of e+e−→Ξ−Ξ¯+, no significant ψ(4230) or ψ(4260) resonance is observed in the Ξ−Ξ¯+ final states, and upper limits at the 90% confidence level on ΓeeB for the processes ψ(4230)/ψ(4260)→Ξ−Ξ¯+ are determined. In addition, an excited Ξ baryon at 1820 MeV/c2 is observed with a statistical significance of 6.2–6.5σ by including the systematic uncertainty, an…
Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356
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Measurement of proton electromagnetic form factors in the time-like region using initial state radiation at BESIII
Physics letters / B 817, 136328 (2021). doi:10.1016/j.physletb.2021.136328
Isomeric state of $^{80}$Y and its role in the astrophysical rp-process
5 pages, 7 figures.-- PACS nrs: 21.10.Tg; 23.20.Nx; 27.50.+e.
Centrality dependence of particle production inp−Pbcollisions atsNN=5.02TeV
We report measurements of the primary charged-particle pseudorapidity density and transverse momentum distributions in p-Pb collisions at root s(NN) = 5.02 TeV and investigate their correlation with experimental observables sensitive to the centrality of the collision. Centrality classes are defined by using different event-activity estimators, i.e., charged-particle multiplicities measured in three different pseudorapidity regions as well as the energy measured at beam rapidity (zero degree). The procedures to determine the centrality, quantified by the number of participants (N-part) or the number of nucleon-nucleon binary collisions (N-coll) are described. We show that, in contrast to Pb…
Centrality dependence of the nuclear modification factor of charged pions, kaons, and protons in Pb-Pb collisions atsNN=2.76TeV
Transverse momentum (pT) spectra of pions, kaons, and protons up to pT=20GeV/c have been measured in Pb-Pb collisions at √sNN=2.76TeV using the ALICE detector for six different centrality classes covering 0%–80%. The proton-to-pion and the kaon-to-pion ratios both show a distinct peak at pT≈3GeV/c in central Pb-Pb collisions that decreases for more peripheral collisions. For pT>10GeV/c, the nuclear modification factor is found to be the same for all three particle species in each centrality interval within systematic uncertainties of 10%–20%. This suggests there is no direct interplay between the energy loss in the medium and the particle species composition in the hard core of the quenched…
J/ψPolarization inppCollisions ats=7 TeV
The ALICE Collaboration has studied J/psi production in pp collisions at root s = 7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/psi polarization parameters lambda(theta) and lambda(phi) were obtained. The study was performed in the kinematic region 2: 5 < y < 4, 2 < p(t) < 8 GeV/c, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.
The driving factors of new particle formation and growth in the polluted boundary layer
Publisher Copyright: © 2021 Mao Xiao et al. New particle formation (NPF) is a significant source of atmospheric particles, affecting climate and air quality. Understanding the mechanisms involved in urban aerosols is important to develop effective mitigation strategies. However, NPF rates reported in the polluted boundary layer span more than 4 orders of magnitude, and the reasons behind this variability are the subject of intense scientific debate. Multiple atmospheric vapours have been postulated to participate in NPF, including sulfuric acid, ammonia, amines and organics, but their relative roles remain unclear. We investigated NPF in the CLOUD chamber using mixtures of anthropogenic vap…
Precision measurement of the matrix elements for $\eta\to\pi^+\pi^-\pi^0$ and $\eta\to\pi^0\pi^0\pi^0$ decays
A precision measurement of the matrix elements for $\eta\to\pi^+\pi^-\pi^0$ and $\eta\to\pi^0\pi^0\pi^0$ decays is performed using a sample of $(10087\pm44)\times10^6$ $J/\psi$ decays collected with the BESIII detector. The decay $J/\psi \to \gamma \eta$ is used to select clean samples of 631,686 $\eta\to\pi^+\pi^-\pi^0$ decays and 272,322 $\eta\to\pi^0\pi^0\pi^0$ decays. The matrix elements for both channels are in reasonable agreement with previous measurements. The non-zero $gX^2Y$ term for the decay mode $\eta\to\pi^+\pi^-\pi^0$ is confirmed, as reported by the KLOE Collaboration, while the other higher-order terms are found to be insignificant. Dalitz plot asymmetries in the $\eta\to\p…
GW170817: Measurements of Neutron Star Radii and Equation of State
On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation…