Search results for "Gluon"
showing 10 items of 697 documents
Constraints on off-shell Higgs boson production and the Higgs boson total width in ZZ → 4ℓ and ZZ → 2ℓ2ν final states with the ATLAS detector
2018
A measurement of off-shell Higgs boson production in the and decay channels, where ℓ stands for either an electron or a muon, is performed using data from proton–proton collisions at a centre-of-mass energy of TeV. The data were collected by the ATLAS experiment in 2015 and 2016 at the Large Hadron Collider, and they correspond to an integrated luminosity of . An observed (expected) upper limit on the off-shell Higgs signal strength, defined as the event yield normalised to the Standard Model prediction, of 3.8 (3.4) is obtained at 95% confidence level (CL). Assuming the ratio of the Higgs boson couplings to the Standard Model predictions is independent of the momentum transfer of the Higgs…
"Table 12: Cross-section limits lepton specific tanb 1" of "Search for a heavy Higgs boson decaying into a $Z$ boson and another heavy Higgs boson in…
2018
The cross section times BR(A->ZH) times BR(H->bb) limits for an A boson in the lepton specific, tanbeta 1, 2HDM. For each signal point, characterised by the mass pair (mA, mH), two limits are provided, the observed and the expected. The correct width as predicted by this particular parameter choice of the 2HDM is used. For lepton specific only gluon-gluon fusion is used and the nb=2 category only.
"Table 14: Cross-section limits lepton specific tanb 3" of "Search for a heavy Higgs boson decaying into a $Z$ boson and another heavy Higgs boson in…
2018
The cross section times BR(A->ZH) times BR(H->bb) limits for an A boson in the lepton specific, tanbeta 3, 2HDM. For each signal point, characterised by the mass pair (mA, mH), two limits are provided, the observed and the expected. The correct width as predicted by this particular parameter choice of the 2HDM is used. For lepton specific only gluon-gluon fusion is used and the nb=2 category only.
"Table 13: Cross-section limits lepton specific tanb 2" of "Search for a heavy Higgs boson decaying into a $Z$ boson and another heavy Higgs boson in…
2018
The cross section times BR(A->ZH) times BR(H->bb) limits for an A boson in the lepton specific, tanbeta 2, 2HDM. For each signal point, characterised by the mass pair (mA, mH), two limits are provided, the observed and the expected. The correct width as predicted by this particular parameter choice of the 2HDM is used. For lepton specific only gluon-gluon fusion is used and the nb=2 category only.
Photon emissivity of the quark-gluon plasma: A lattice QCD analysis of the transverse channel
2022
We present results for the thermal photon emissivity of the quark-gluon plasma derived from spatially transverse vector correlators computed in lattice QCD at a temperature of 250 MeV. The analysis of the spectral functions, performed at fixed spatial momentum, is based on continuum-extrapolated correlators obtained with two flavours of dynamical Wilson fermions. We compare the next-to-leading order perturbative QCD correlators, as well as the ${\cal N}=4$ supersymmetric Yang-Mills correlators at infinite coupling, to the correlators from lattice QCD and find them to lie within $\sim10\%$ of each other. We then refine the comparison, performing it at the level of filtered spectral functions…
Search for a common baryon source in high-multiplicity pp collisions at the LHC
2020
Physics letters / B B811, 135849 (2020). doi:10.1016/j.physletb.2020.135849
Particle identification in ALICE: a Bayesian approach
2016
We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss ($\mathrm{d}E/\mathrm{d}x$) and time-of-flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels ${\rm K}^0_S \righta…
Investigation of the p–Σ0 interaction via femtoscopy in pp collisions
2020
This Letter presents the first direct investigation of the p-$\Sigma^{0}$ interaction, using the femtoscopy technique in high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV measured by the ALICE detector. The $\Sigma^{0}$ is reconstructed via the decay channel to $\Lambda \gamma$, and the subsequent decay of $\Lambda$ to p$\pi^-$. The photon is detected via the conversion in material to e$^{+}$e$^{-}$ pairs exploiting the unique capability of the ALICE detector to measure electrons at low transverse momenta. The measured p-$\Sigma^{0}$ correlation indicates a shallow strong interaction. The comparison of the data to several theoretical predictions obtained employing the $Correlation~Anal…
Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC
2018
We report the measured transverse momentum ($p_{\rm T}$) spectra of primary charged particles from pp, p-Pb and Pb-Pb collisions at a center-of-mass energy $\sqrt{s_{\rm NN}} = 5.02$ TeV in the kinematic range of $0.15<p_{\rm T}<50$ GeV/$c$ and $|\eta|< 0.8$. A significant improvement of systematic uncertainties motivated the reanalysis of data in pp and Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV, as well as in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV, which is also presented. Spectra from Pb-Pb collisions are presented in nine centrality intervals and are compared to a reference spectrum from pp collisions scaled by the number of binary nucleon-nucleon collisions. For cent…
Characterizing the initial conditions of heavy-ion collisions at the LHC with mean transverse momentum and anisotropic flow correlations
2022
Physics letters / B 834, 137393 (2022). doi:10.1016/j.physletb.2022.137393