The production of pion, kaon and proton was measured in Pb–Pb collisions at nucleus–
18 nucleus center-of-mass energy √sNN = 2.76 TeV by the ALICE experiment at Large
19 Hadron Collider (LHC). The particle ratios of these species compared to the RHIC mea20
surements are confronted to the hadron resonance gas (HRG) model and to simulations
21 based on the event generators PYTHIA 6.4.21 and HIJING 1.36. It is found that the
22 homogeneous particle–antiparticle ratios (same species) are fully reproducible by means
23 of HRG and partly by PYTHIA 6.4.21 and HIJING 1.36. The mixed kaon–pion and
24 proton–pion ratios measured at RHIC and LHC energies seem to be reproducible by the
25 HRG model. On the other hand, the strange abundances are underestimated in both
26 event generators. This might be originated to strangeness suppression in the event gener27
ators and/or possible strangeness enhancement in the experimental data. It is apparent
28 that the values of kaon–pion ratios are not sensitive to the huge increase of √sNN from
29 200 (RHIC) to 2760 GeV (LHC). We conclude that the ratios of produced particle at
30 LHC seem not depending on the system size. |
