Production of the ρ(770)⁰ meson in pp and Pb-Pb collisions at √s_NN = 2.76 TeV

The production of the ρ(770)⁰ meson has been measured at midrapidity (|y|<0.5) in pp and centrality differential Pb-Pb collisions at √sNN= 2.76 TeV with the ALICE detector at the Large Hadron Collider. The particles have been reconstructed in the ρ(770)⁰→π⁺π^- decay channel in the transverse-momentum (pT) range 0.5-11 GeV/c. A centrality-dependent suppression of the ratio of the integrated yields 2ρ(770)⁰/(π⁺+π^-) is observed. The ratio decreases by ∼40% from pp to central Pb-Pb collisions. A study of the pT-differential 2ρ(770)⁰/(π⁺+π^-) ratio reveals that the suppression occurs at low transverse momenta, p_T < 2 GeV/c. At higher momentum, particle ratios measured in heavy-ion and pp collisions are consistent. The observed suppression is very similar to that previously measured for the K^∗(892)⁰/K ratio and is consistent with EPOS3 predictions that may imply that rescattering in the hadronic phase is a dominant mechanism for the observed suppression.