In-Medium Effective Axial-Vector Coupling Constant

الأصل · EN

The axial-vector coupling constant in nuclear medium is systematically studied using chiral perturbation theory. For normal nuclear matter, the first non-trivial corrections are estimated based on the independent particle approximation taking into account nuclear correlations in nuclear medium. The one-pion-exchange (OPE) two-body interactions turn out to enhance the coupling constant by δgₐ/gₐ≃ (0.09 0.15). The role of the four-nucleon contact interaction, whose low-energy constants are yet to be determined, is analyzed in connection with the empirical quenching factor of δgₐ/gₐ≃ -0.2 in the presence of the nuclear short-range correlation. Conventional approaches are discussed in the light of our result.