Semi-empirical mass formula for Λ-hypernuclei

Abstract

We have studied the Λ-dependence of the separation energy, SΛ, of the Λ-hyperon in Λ-hypernuclei by fitting the parameters of a semi-empirical mass formula employed in previous works, which is based on the hypernuclear finite size. We extend this formula by considering two corrections: one takes into account the finite mass of the hypernucleus in terms of a Λ reduced mass and the other implements the effects of charge symmetry breaking (CSB). Both corrections are found non-negligible for finite hypernuclei. Moreover, our study reveals some inconsistencies in the SΛ data of mirror hypernuclei, preventing us from obtaining a well-determined CSB parameter