Suppression of ϒ(1S) at forward rapidity in Pb-Pb collisions at sNN=2.76 TeV

Abstract

We report on the measurement of the inclusive ϒ{hooked}(1S) production in Pb-Pb collisions at sNN=2.76 TeV carried out at forward rapidity (2.5<y<4) and down to zero transverse momentum using its μ+μ- decay channel with the ALICE detector at the Large Hadron Collider. A strong suppression of the inclusive ϒ{hooked}(1S) yield is observed with respect to pp collisions scaled by the number of independent nucleon-nucleon collisions. The nuclear modification factor, for events in the 0-90% centrality range, amounts to 0.30±0.05(stat)±0.04(syst). The observed ϒ{hooked}(1S) suppression tends to increase with the centrality of the collision and seems more pronounced than in corresponding mid-rapidity measurements. Our results are compared with model calculations, which are found to underestimate the measured suppression and fail to reproduce its rapidity dependence. © 2014 The Authors.