3?H and 3?H production in Pb-Pb collisions at ?sNN=2.76 TeV

Abstract

The production of the hypertriton nuclei H?3 and H[U+203E]?-3 has been measured for the first time in Pb-Pb collisions at sNN=2.76 TeV with the ALICE experiment at LHC. The pT-integrated H?3 yield in one unity of rapidity, dN/dy�B.R.(H?3?He3,?-)=(3.86�0.77(stat.)�0.68(syst.))�10-in 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 B3 shows a dependence on the transverse momentum, similar to the B2 of deuterons and the B3 of 3He nuclei. The ratio of yields S3=H?3/(He3�?/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 S3 is compatible with thermal model predictions. The measured H?3 lifetime, ?=181-39+54(stat.)�33(syst.)ps is in agreement within 1? with the world average value. � 2016 CERN for the benefit of the ALICE Collaboration.