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Resonance production in Pb+Pb collisions at 5.02 TeV
The yields, mean transverse momenta, and flow of K *0 , ρ 0 , Λ(1520) resonances provide an evidence of a late stage hadronic rescattering in ultrarelativistic central heavy ion collisions [1]. Using hydrodynamic + hadronic afterburner simulations of Pb+Pb collisions at 5.02 TeV we achieve a reasonable description of resonance yields and spectra as a function of collision centrality. We demonstrate that the measurements of Λ(1520)’s mean transverse momentum allow to constrain the unknown branching ratios of Σ* → Λ(1520)π decays. Hadronic dynamics leads to an enhanced ∆(1232) production in central collisions.
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NSF-PAR ID:
10333924
Journal Name:
EPJ Web of Conferences
Volume:
259
Page Range or eLocation-ID:
10008
ISSN:
2100-014X
1. A bstract Measurements of elliptic ( v 2 ) and triangular ( v 3 ) flow coefficients of π ± , K ± , p+ $$\overline{\mathrm{p}}$$ p ¯ , $${\mathrm{K}}_{\mathrm{S}}^0$$ K S 0 , and Λ+ $$\overline{\Lambda}$$ Λ ¯ obtained with the scalar product method in Xe-Xe collisions at $$\sqrt{s_{\mathrm{NN}}}$$ s NN = 5 . 44 TeV are presented. The results are obtained in the rapidity range | y | < 0 . 5 and reported as a function of transverse momentum, p T , for several collision centrality classes. The flow coefficients exhibit a particle mass dependence for p T < 3 GeV/ c , while a grouping according to particle type (i.e., meson and baryon) is found at intermediate transverse momenta (3 < p T < 8 GeV/ c ). The magnitude of the baryon v 2 is larger than that of mesons up to p T = 6 GeV/ c . The centrality dependence of the shape evolution of the p T -differential v 2 is studied for the various hadron species. The v 2 coefficients of π ± , K ± , and p+ $$\overline{\mathrm{p}}$$ pmore »
2. A bstract The production of prompt D 0 , D + , and D *+ mesons was measured at midrapidity (| y | < 0.5) in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair $$\sqrt{s_{\mathrm{NN}}}$$ s NN = 5 . 02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decay channels and their production yields were measured in central (0–10%) and semicentral (30–50%) collisions. The measurement was performed up to a transverse momentum ( p T ) of 36 or 50 GeV/c depending on the D meson species and the centrality interval. For the first time in Pb–Pb collisions at the LHC, the yield of D 0 mesons was measured down to p T = 0, which allowed a model-independent determination of the p T -integrated yield per unit of rapidity (d N/ d y ). A maximum suppression by a factor 5 and 2.5 was observed with the nuclear modification factor ( R AA ) of prompt D mesons at p T = 6–8 GeV/c for the 0–10% and 30–50% centrality classes, respectively. The D-meson R AA is compared with that of charged pions, charged hadrons, and Jmore »
3. Abstract Measurements of event-by-event fluctuations of charged-particle multiplicities in Pb–Pb collisions at $$\sqrt{s_{\mathrm {NN}}}$$ s NN   $$=$$ =  2.76 TeV using the ALICE detector at the CERN Large Hadron Collider (LHC) are presented in the pseudorapidity range $$|\eta |<0.8$$ | η | < 0.8 and transverse momentum $$0.2< p_{\mathrm{T}} < 2.0$$ 0.2 < p T < 2.0  GeV/ c . The amplitude of the fluctuations is expressed in terms of the variance normalized by the mean of the multiplicity distribution. The $$\eta$$ η and $$p_{\mathrm{T}}$$ p T dependences of the fluctuations and their evolution with respect to collision centrality are investigated. The multiplicity fluctuations tend to decrease from peripheral to central collisions. The results are compared to those obtained from HIJING and AMPT Monte Carlo event generators as well as to experimental data at lower collision energies. Additionally, the measured multiplicity fluctuations are discussed in the context of the isothermal compressibility of the high-density strongly-interacting system formed in central Pb–Pb collisions.
4. A bstract A measurement of the inclusive b-jet production cross section is presented in pp and p-Pb collisions at $$\sqrt{s_{\mathrm{NN}}}$$ s NN = 5 . 02 TeV, using data collected with the ALICE detector at the LHC. The jets were reconstructed in the central rapidity region |η| < 0 . 5 from charged particles using the anti- k T algorithm with resolution parameter R = 0 . 4. Identification of b jets exploits the long lifetime of b hadrons, using the properties of secondary vertices and impact parameter distributions. The p T -differential inclusive production cross section of b jets, as well as the corresponding inclusive b-jet fraction, are reported for pp and p-Pb collisions in the jet transverse momentum range 10 ≤ p T , ch jet ≤ 100 GeV/ c , together with the nuclear modification factor, $${R}_{\mathrm{pPb}}^{\mathrm{b}-\mathrm{jet}}$$ R pPb b − jet . The analysis thus extends the lower p T limit of b-jet measurements at the LHC. The nuclear modification factor is found to be consistent with unity, indicating that the production of b jets in p-Pb at $$\sqrt{s_{\mathrm{NN}}}$$ s NN = 5 . 02 TeV is not affected bymore »
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