Multiplicity dependence of charged pion, kaon, and (anti)proton production at large transverse momentum in p–Pb collisions at √s_NN=5.02 TeV

The production of charged pions, kaons and (anti)protons has been measured at mid-rapidity (−0.5<y<0) in p–Pb collisions at s_NN=5.02 TeV using the ALICE detector at the LHC. Exploiting particle identification capabilities at high transverse momentum (p_T), the previously published p_T spectra have been extended to include measurements up to 20 GeV/c for seven event multiplicity classes. The p_T spectra for pp collisions at s=7 TeV, needed to interpolate a pp reference spectrum, have also been extended up to 20 GeV/c to measure the nuclear modification factor (R_pPb) in non-single diffractive p–Pb collisions. At intermediate transverse momentum (2<p_T<10 GeV/c) the proton-to-pion ratio increases with multiplicity in p–Pb collisions, a similar effect is not present in the kaon-to-pion ratio. The p_T dependent structure of such increase is qualitatively similar to those observed in pp and heavy-ion collisions. At high p_T (>10 GeV/c), the particle ratios are consistent with those reported for pp and Pb–Pb collisions at the LHC energies. At intermediate p_T the (anti)proton R_pPb shows a Cronin-like enhancement, while pions and kaons show little or no nuclear modification. At high p_T the charged pion, kaon and (anti)proton R_pPb are consistent with unity within statistical and systematic uncertainties.