Ab initio calculation of charge-symmetry breaking in A=7 and 8 A hypernuclei

The A separation energies of the isospin triplet 7A He, 7A Li*, 7A Be, and the T = 1/2 doublet 8A Li, 8A Be are investigated within the no-core shell model. Calculations are performed based on a hyperon-nucleon potential derived from chiral effective field theory at next-to-leading order. The potential includes the leading charge -symmetry breaking (CSB) interaction in the AN channel, whose strength has been fixed to the experimentally known difference of the A separation energies of the mirror hypernuclei 4AHe and 4AH. It turns out that the CSB predicted for the A = 7 systems is small and agrees with the splittings deduced from the empirical binding energies within the experimental uncertainty. In the case of the A = 8 doublet, the computed CSB is somewhat larger than the available experimental value.

Automated summary

This study investigates the separation energies of the isospin triplet 7A He, 7A Li*, 7A Be, and the T = 1/2 doublet 8A Li, 8A Be using the no-core shell model. The calculations are based on a hyperon-nucleon potential derived from chiral effective field theory. The results show that the predicted charge-symmetry breaking (CSB) in the A = 7 systems agrees with the empirical binding energies within experimental uncertainty, while in the A = 8 doublet, the computed CSB is slightly larger than the experimental value.