Quenching of spin operators in the calculation of radiative corrections for nuclear beta decay

Abstract

Calculations of the axial-vector component to the radiative correction for superallowed Fermi $0^{+}\to 0^{+}$ nuclear beta decay are here modified with quenched rather than free-nucleon coupling constants for the axial-vector and electromagnetic interactions with nucleons. The result increases the deduced value of $V_{ud}$ but does not restore unitarity in the CKM matrix.

Comments: LaTeX, 7 pages, no figures, TASCC-P-94-11