Production of 4He and 4He‾ in Pb–Pb collisions at √sNN=2.76 TeV at the LHC

Abstract

Results on the production of 4He and 4He nuclei in Pb–Pb collisions at √sNN=2.76TeV in the rapidity range |y|<1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0–10% central events are found to be dN/dy4He=(0.8±0.4(stat)±0.3(syst))×10−6 and dN/dy4He=(1.1 ±0.4(stat) ±0.2(syst)) ×10−6, respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (Tchem=156 MeV) as for light hadrons. The measured ratio of 4He‾/4He is 1.4 ±0.8(stat) ±0.5(syst).