On the measured lifetime of light hypernuclei 3ΛH and 4ΛH

A statistical combination of the experimental lifetime estimations available in the literatures is performed for 3ΛH and 4ΛH, including several recent measurements. The combined average values of the lifetime for 3ΛH and 4ΛH are respectively 216−16+19 ps and 192−18+20 ps with a reduced χ2χ2 of 0.89 and 0.48. A new insight into the lifetime estimation of the HypHI Phase 0 experiment by a Bayesian approach is also presented. In this approach, several different prior distributions including the combination of previous lifetime data and a Jeffrey prior are used. The principal mode and the smallest credible interval at 68% of the posterior distribution, given by the prior belief of the previous measurements, are 217−16+19 ps and 194−18+20 ps respectively for 3ΛH and 4ΛH. The two employed approaches have revealed that the lifetime of hypernuclei 3ΛH and 4ΛH can be shorter than the Λ–hyperon lifetime.