Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at √sNN=2.76TeV

Abstract

Transverse momentum spectra of π±, K±and p(¯ p)up to pT=20GeV/cat mid-rapidity in pp, peripheral (60–80%) and central (0–5%) Pb–Pb collisions at √sNN=2.76TeVhave been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pion ratios both show adistinct peak at pT≈3GeV/cin central Pb–Pb collisions. Below the peak, pT<3GeV/c, both ratios are in good agreement with hydrodynamical calculations, suggesting that the peak itself is dominantly the result of radial flow rather than anomalous hadronization processes. For pT>10GeV/cparticle ratios in ppand Pb–Pb collisions are in agreement and the nuclear modification factors for π±, K±and p(¯ p)indicate that, within the systematic and statistical uncertainties, the suppression is the same. This suggests that the chemical composition of leading particles from jets in the medium is similar to that of vacuum jets.