Neutral meson production in pp and Pb-Pb collisions measured by ALICE at the LHC

Abstract

The midrapidity $\pi^0$ nuclear modification factor, $R_{\rm{AA}}$, at $\sqrt{s_\mathrm{NN}} =$ 2.76 TeV in 6 centrality classes as well as the corresponding $\pi^0$ invariant yields in Pb-Pb and in pp collisions are presented. The transverse momentum range covered is 0.6 (0.4) GeV/$c$ $< p_{\mathrm{T}} <$ 12 (10) GeV/$c$ for Pb-Pb (pp) collisions. A suppression of neutral pions increasing with centrality is observed. The yield of charged particles associated with a high $p_{\mathrm{T}}$ neutral pion trigger (8 GeV/$c$ $< p_{\mathrm{T}} <$ 16 GeV/$c$) is measured in pp and Pb-Pb collisions at $\sqrt{s_\mathrm{NN}} =$ 2.76 TeV. The conditional per-trigger yield modification factor in the near and away side is in agreement with the measured one for charged particles.