Transverse momentum spectra and nuclear modification factors of identified charged hadrons in p-Pb and Pb-Pb collisions at √s _NN = 5.02 TeV with ALICE

摘要

The ALICE experiment has measured the production of identified light-flavour hadrons in p-Pb and Pb-Pb collisions at 5.02 TeV in a wide range of transverse momentum. The newest ALICE results on pion, kaon and proton transverse momentum spectra, yield ratios and nuclear modification factors will be presented and discussed in comparison to lower energy results. In particular, the production of identified hadrons in most central Pb-Pb collisions relative to pp collisions is found to be strongly suppressed at high transverse momenta (pT > 8 GeV/c) whereas in p-Pb collisions the nuclear modification factors are consistent with unity. This indicates that the strong suppression of high-pT hadrons measured in central Pb-Pb collisions is not due to an initial state effect but instead to the energy loss of partons traversing a hot and dense QCD medium.