Search results for "SPECTRA"
showing 10 items of 3542 documents
High resolution study of the 3ν1 band of SO2
2009
Abstract The second overtone band 3 ν 1 of sulfur dioxide has been studied for the first time with high resolution rotation-vibration spectroscopy. About 3000 transitions involving about 900 upper state energy levels with J max. = 66 and K a max. = 24 have been assigned to the 3 ν 1 band. In the analysis, an effective Hamiltonian taking into account accidental interactions between the vibrational states (3 0 0), (2 2 0), and (0 4 1) was used. The Watson operator in A -reduction and I r representation was used in the diagonal blocks of the Hamiltonian. As the result of analysis a set of parameters reproducing the initial experimental data with the rms = 0.00028 cm −1 was obtained.
Theoretical study of resonant x-ray emission spectroscopy of Mn films on Ag.
2006
We report a theoretical study on resonant x-ray emission spectra (RXES) in the whole energy region of the Mn $L_{2,3}$ white lines for three prototypical Mn/Ag(001) systems: (i) a Mn impurity in Ag, (ii) an adsorbed Mn monolayer on Ag, and (iii) a thick Mn film. The calculated RXES spectra depend strongly on the excitation energy. At $L_3$ excitation, the spectra of all three systems are dominated by the elastic peak. For excitation energies around $L_2$, and between $L_3$ and $L_2$, however, most of the spectral weight comes from inelastic x-ray scattering. The line shape of these inelastic ``satellite'' structures changes considerably between the three considered Mn/Ag systems, a fact tha…
Production of charged pions, kaons, and (anti-)protons in Pb-Pb and inelastic pp collisions at sNN=5.02 TeV
2020
Mid-rapidity production of $\pi^{\pm}$, $\rm{K}^{\pm}$ and ($\bar{\rm{p}}$)p measured by the ALICE experiment at the LHC, in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, is presented. The invariant yields are measured over a wide transverse momentum ($p_{\rm{T}}$) range from hundreds of MeV/$c$ up to 20 GeV/$c$. The results in Pb-Pb collisions are presented as a function of the collision centrality, in the range 0$-$90%. The comparison of the $p_{\rm{T}}$-integrated particle ratios, i.e. proton-to-pion (p/$\pi$) and kaon-to-pion (K/$\pi$) ratios, with similar measurements in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV show no significant energy dependence. B…
Unveiling ν secrets with cosmological data: Neutrino masses and mass hierarchy
2017
Using some of the latest cosmological datasets publicly available, we derive the strongest bounds in the literature on the sum of the three active neutrino masses, $M_\nu$, within the assumption of a background flat $\Lambda$CDM cosmology. In the most conservative scheme, combining Planck cosmic microwave background (CMB) temperature anisotropies and baryon acoustic oscillations (BAO) data, as well as the up-to-date constraint on the optical depth to reionization ($\tau$), the tightest $95\%$ confidence level (C.L.) upper bound we find is $M_\nu0.06\,{\rm eV}$ from oscillations data would raise the quoted upper bounds by ${\cal O}(0.1\sigma)$ and would not affect our conclusions.
Robust measurement of supernova νe spectra with future neutrino detectors
2017
Measuring precise all-flavor neutrino information from a supernova is crucial for understanding the core-collapse process as well as neutrino properties. We apply a chi-squared analysis for different detector setups to explore determination of $\nu_{e}$ spectral parameters. Using a long-term two-dimensional core-collapse simulation with three time varying spectral parameters, we generate mock data to examine the capabilities of the current Super-Kamiokande detector and compare the relative improvements that gadolinium, Hyper-Kamiokande, and DUNE would have. We show that in a realistic three spectral parameter framework, the addition of gadolinium to Super-Kamiokande allows for a qualitative…
Neutrino Unification
2000
Present neutrino data are consistent with neutrino masses arising from a common seed at some ``neutrino unification'' scale $M_X$. Such a simple theoretical ansatz naturally leads to quasi-degenerate neutrinos that could lie in the electron-volt range with neutrino mass splittings induced by renormalization effects associated with supersymmetric thresholds. In such a scheme the leptonic analogue of the Cabibbo angle $\theta_{\odot}$ describing solar neutrino oscillations is nearly maximal. Its exact value is correlated with the smallness of $\theta_{reactor}$. These features agree both with latest data on the solar neutrino spectra and with the reactor neutrino data. The two leading mass-ei…
The present and future of the most favoured inflationary models after $Planck$ 2015
2015
The value of the tensor-to-scalar ratio $r$ in the region allowed by the latest $Planck$ 2015 measurements can be associated to a large variety of inflationary models. We discuss here the potential of future Cosmic Microwave Background cosmological observations in disentangling among the possible theoretical scenarios allowed by our analyses of current $Planck$ temperature and polarization data. Rather than focusing only on $r$, we focus as well on the running of the primordial power spectrum, $\alpha_s$ and the running of thereof, $\beta_s$. Our Fisher matrix method benefits from a detailed and realistic appraisal of the expected foregrounds. Future cosmological probes, as the COrE mission…
Measurements of the Nuclear Modification Factor for Jets inPb+PbCollisions atsNN=2.76 TeVwith the ATLAS Detector
2015
Measurements of inclusive jet production are performed in pp and Pb+Pb collisions at √sNN = 2.76 TeV with the ATLAS detector at the LHC, corresponding to integrated luminosities of 4.0 pb−1 and 0.14 nb−1, respectively. The jets are identified with the anti-kt algorithm with R = 0.4, and the spectra are measured over the kinematic range of jet transverse momentum 32 < pT < 500 GeV, and absolute rapidity |y| < 2.1 and as a function of collision centrality. The nuclear modification factor, RAA, is evaluated and jets are found to be suppressed by approximately a factor of two in central collisions compared to pp collisions. The RAA shows a slight increase with pT and no significant variation wi…
KS0andΛProduction in Pb-Pb Collisions atsNN=2.76 TeV
2013
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…
Bounds on an Anomalous Dijet Resonance inW+jetsProduction inpp¯Collisions ats=1.96 TeV
2011
We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a $W$ boson in data corresponding to an integrated luminosity of 4.3 fb$^{-1}$ collected with the D0 detector at $\sqrt{s} =1.96$ TeV. We find no evidence for anomalous resonant dijet production and derive upper limits on the production cross section of an anomalous dijet resonance recently reported by the CDF Collaboration, investigating the range of dijet invariant mass from 110 to 170 GeV/$c^2$. The probability of the D0 data being consistent with the presence of a dijet resonance with 4 pb production cross section at 145 GeV/$c^2$ is $8\times 10^{-6}$.