We present results on transverse momentum (pT) and rapidity (y) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive J/ψ and ψ(2S) at ...forward rapidity (2.5 < y < 4) as well as ψ(2S)-to-J/ψ cross section ratios. These quantities are measured in pp collisions at center of mass energies √s = 5.02 and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at √s = 2.76, 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full pT range, provided that both contributions are summed. In particular, it is found that for pT > 15 GeV/c the non-prompt contribution reaches up to 50% of the total charmonium yield.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p–Pb collisions at √sNN = 5.02 TeV were measured in the rapidity range –0.5 ...< yCMS < 0 for event classes corresponding to different charged-particle multiplicity densities, < dNch/dηlab >. The mean transverse momentum values are presented as a function of < dNch/dηlab >, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of < dNch/dηlab >. The equivalent ratios to pions exhibit an increase with < dNch/dηlab >, depending on their strangeness content.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The W and Z boson production was measured via the muonic decay channel in proton-lead collisions at √sNN = 5.02 TeV at the Large Hadron Collider with the ALICE detector. The measurement covers ...backward (–4.46 < ycms < –2.96) and forward (2.03 < ycms < 3.53) rapidity regions, corresponding to Pb-going and p-going directions, respectively. The Z-boson production cross section, with dimuon invariant mass of 60 < mμμ < 120 GeV/c2 and muon transverse momentum (pTμ) larger than 20 GeV/c, is measured. The production cross section and charge asymmetry of muons from W-boson decays with pTμ > 10 GeV/c are determined. The results are compared to theoretical calculations both with and without including the nuclear modification of the parton distribution functions. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions within uncertainties.
We present results on transverse momentum (Formula: see text) and rapidity (Formula: see text) differential production cross sections, mean transverse momentum and mean transverse momentum square of ...inclusive Formula: see text and Formula: see text at forward rapidity (Formula: see text) as well as Formula: see text-to-Formula: see text cross section ratios. These quantities are measured in pp collisions at center of mass energies Formula: see text and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at Formula: see text, 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full Formula: see text range, provided that both contributions are summed. In particular, it is found that for Formula: see text GeV/
the non-prompt contribution reaches up to 50% of the total charmonium yield.
We report the measurements of correlations between event-by-event fluctuations of amplitudes of anisotropic flow harmonics in nucleus-nucleus collisions, obtained for the first time using a new ...analysis method based on multiparticle cumulants in mixed harmonics. This novel method is robust against systematic biases originating from nonflow effects and by construction any dependence on symmetry planes is eliminated. We demonstrate that correlations of flow harmonics exhibit a better sensitivity to medium properties than the individual flow harmonics. The new measurements are performed in Pb-Pb collisions at the center-of-mass energy per nucleon pair of sqrts_{NN}=2.76 TeV by the ALICE experiment at the Large Hadron Collider. The centrality dependence of correlation between event-by-event fluctuations of the elliptic v_{2} and quadrangular v_{4} flow harmonics, as well as of anticorrelation between v_{2} and triangular v_{3} flow harmonics are presented. The results cover two different regimes of the initial state configurations: geometry dominated (in midcentral collisions) and fluctuation dominated (in the most central collisions). Comparisons are made to predictions from Monte Carlo Glauber, viscous hydrodynamics, ampt, and hijing models. Together with the existing measurements of the individual flow harmonics the presented results provide further constraints on the initial conditions and the transport properties of the system produced in heavy-ion collisions.
Abstract The invariant differential cross sections for inclusive $$\pi ^{0}$$ π 0 and $$\eta $$ η mesons at midrapidity were measured in pp collisions at $$\sqrt{s}=2.76$$ s = 2.76 TeV for ...transverse momenta $$0.4<p_{\mathrm {T}}<40$$ 0.4 < p T < 40 GeV/c and $$0.6<p_{\mathrm {T}}<20$$ 0.6 < p T < 20 GeV/c, respectively, using the ALICE detector. This large range in $$p_{\mathrm {T}}$$ p T was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high- $$p_{\mathrm {T}}$$ p T neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/ $$c$$ c , the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the $$\pi ^{0}$$ π 0 , and between 30–50% for the $$\eta $$ η meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10–30%, except at $$p_{\mathrm {T}}<1$$ p T < 1 GeV/ $$c$$ c . The new data can therefore be used to further improve the theoretical description of $$\pi ^{0}$$ π 0 and $$\eta $$ η meson production.
The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ(1385)±, Ξ(1530)0) produced in p–Pb collisions at sNN=5.02 TeV were measured in the rapidity range ...-0.5<yCMS<0 for event classes corresponding to different charged-particle multiplicity densities, ⟨dNch/dηlab⟩. The mean transverse momentum values are presented as a function of ⟨dNch/dηlab⟩, as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨dNch/dηlab⟩. The equivalent ratios to pions exhibit an increase with ⟨dNch/dηlab⟩, depending on their strangeness content.
The charged particle multiplicity distributions measured by two experiments, WA97 and NA57, in Pb+Pb collisions at 158 A GeV/c have been analyzed in the framework of the Wounded Nucleon Model (WNM). ...We obtain a good description of the data within the centrality range of our samples. This allows us to make use of the measured multiplicities to estimate the number of wounded nucleons of the collision.
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