Parameter counting in relativistic mean-field models

Abstract

Power counting is applied to relativistic mean-field energy functionals to estimate contributions to the energy from individual terms. New estimates for isovector, tensor, and gradient terms in finite nuclei are shown to be consistent with direct, high-quality fits. The estimates establish a hierarchy of model parameters and identify how many parameters are well constrained by bulk nuclear observables. We conclude that four (possibly five) isoscalar, non-gradient parameters, one gradient parameter, and one isovector parameter are well determined by the usual bulk nuclear observables.