3ΛH and -3Λ-H production in Pb-Pb collisions at √sNN=2.76 TeV

Abstract

The production of the hypertriton nuclei 3_Hand 3¯_Hhas been measured for the first time in Pb–Pbcollisions at √sNN=2.76TeVwith the ALICE experiment at LHC. The pT-integrated 3_Hyield in one unity of rapidity, dN/dy ×B.R. _3_H→3He,π− _=(3.86±0.77(stat.)±0.68(syst.))×10−5in the 0–10%most central collisions, is consistent with the predictions from a statistical thermal model using the same temperature as for the light hadrons. The coalescence parameter B3shows a dependence on the transverse momentum, similar to the B2of deuterons and the B3of 3He nuclei. The ratio of yields S3=3_H/(3He×_/p)was measured to be S3=0.60 ±0.13(stat.) ±0.21(syst.)in 0–10%centrality events; this value is compared to different theoretical models. The measured S3is compatible with hermal model predictions. The measured 3_Hlifetime, τ=181+54−39(stat.) ±33(syst.) psis in agreement within 1σwith the world average value.