Meson Exchange Corrections to Nuclear Weak Axial Charge Density in Hard Pion Model and O exp + Reversible O exp - Transition in A = 16 Nuclei

摘要

Starting with the hard pion model based on a minimal chiral invariant phenomenological Lagrangian, the two-particle part of the time component of the weak axial-vector current is constructed in the tree-approximation. Pion, rho- and A sub 1 -meson exchanges are considered. The mesonic exchange operator obtained is applied to describe the purely weak axial 0 exp + reversible 0 exp - , delta T=1 transition in the nuclear A=16 system, the muon reaction mu exp - + sup 16 O(0 sub 1+ ; T=0) yields sup 16 N(0 sub 1- ; T=1) + gamma sub( mu ) and beta decay sup 16 N(0 sub 1- ; T=1) yields sup 16 O(0 sub 1+ ; T=0) + e exp - + anti nu sub(e). In order to treat nuclear structure correlation effects explicitly use of shell model wave functions with configuration mixing is made. The large enhancement of the nuclear weak axial charge density with respect to impulse approximation is established. (Atomindex citation 15:029913)