Neutral pion production at midrapidity in pp and Pb–Pb collisions at $$\sqrt{s_{{\mathrm {NN}}}}= 2.76\,{\mathrm {TeV}}$$ s NN = 2.76 TeV

Abstract

Invariant yields of neutral pions at midrapidity in the transverse momentum range 0.6 < p T < 12 GeV/c measured in Pb-Pb collisions at s NN = 2.76 TeV are presented for six centrality classes. The pp reference spectrum was measured in the range 0.4 < p T < 10 GeV/c at the same centerof-mass energy. The nuclear modification factor, R AA , shows a suppression of neutral pions in central Pb-Pb collisions by a factor of up to about 8-10 for 5 p T 7 GeV/c. The presented measurements are compared with results at lower center-of-mass energies and with theoretical calculations.