Determine whether Sigma hypernuclei are bound

Determine whether Sigma-hypernuclei are actually bound, thereby constraining the Sigma single-particle potential and the hyperonic coupling constants used in relativistic mean-field models of dense matter.

Background

The relativistic mean-field equation of state considered in the paper includes the full baryonic octet. The coupling of the Sigma hyperon to the scalar meson is calibrated using an assumed Sigma single-particle potential in symmetric nuclear matter at saturation density, but the assumed value is acknowledged to be somewhat arbitrary because the relevant experimental information is limited.

The existence and binding of Sigma-hypernuclei would provide direct empirical guidance for this choice and would reduce uncertainty in the predicted composition and structure of hyperonic neutron stars.