On the measured lifetime of light hypernuclei $^3_\Lambda H$ and $^4_\Lambda H$

A statistical combination of the experimental lifetime estimations available in the literatures is performed for 3 Λ H and 4 Λ H, including several recent measurements. The combined average values of the lifetime for 3 Λ H and 4 Λ H are respectively 216−16+19 ps and 192−18+20 ps with a reduced χ2 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 3 Λ H and 4 Λ H. The two employed approaches have revealed that the lifetime of hypernuclei 3 Λ H and 4 Λ H can be shorter than the Λ –hyperon lifetime.