6533b7cffe1ef96bd1259a5f

RESEARCH PRODUCT

HΛ3 and H‾Λ¯3 production in Pb–Pb collisions at sNN=2.76 TeV

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Abstract The production of the hypertriton nuclei H Λ 3 and H ‾ Λ ¯ 3 has been measured for the first time in Pb–Pb collisions at s NN = 2.76  TeV with the ALICE experiment at LHC. The p T -integrated H Λ 3 yield in one unity of rapidity, d N / d y × B . R . ( H Λ 3 → He 3 , π − ) = ( 3.86 ± 0.77 ( stat. ) ± 0.68 ( syst. ) ) × 10 − 5 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 B 3 shows a dependence on the transverse momentum, similar to the B 2 of deuterons and the B 3 of 3He nuclei. The ratio of yields S 3 = H Λ 3 / ( He 3 × Λ / p ) was measured to be S 3 = 0.60 ± 0.13 ( stat. ) ± 0.21 ( syst. ) in 0–10% centrality events; this value is compared to different theoretical models. The measured S 3 is compatible with thermal model predictions. The measured H Λ 3 lifetime, τ = 181 − 39 + 54 ( stat. ) ± 33 ( syst. ) ps is in agreement within 1σ with the world average value.