Semi-leptonic beta-decay form factors and magnetic moments of octet baryons: Recoil effects and center-of-mass corrections in the cloudy bag model including gluonic effects

Abstract

In a previous article we made a detailed study of the weak interaction form factors and the magnetic moments of the octet baryons. The volume-type cloudy bag model was used as a possible framework for incorporating mesonic contributions in a systematic manner, and, furthermore, gluonic effects were included through evaluating one-gluon exchange diagrams. Despite the rather detailed treatment of these dynamical effects, the previous work was based on the static bag picture and fell short of including such kinematical effects as: (i) recoil corrections and (ii) center-of-mass corrections. One of the purposes of the present work is to investigate these kinematical effects and examine their influences on the results of the previous calculations based on the static bag picture. A second purpose of the present paper is to provide an extensive comparison of the calculated results with the existing experimental data. Regarding the weak interaction form factors of the hyperon beta-decays, it is customary to compare the theoretical values with the “semi-empirical” values obtained through Cabibbo-type fitting to the data, rather than directly dealing with the experimental observables. We make here a direct comparison of the theoretical prediction for various observables with the measured values. In particular, an attempt is made to determine the best-fit values of the Kobayashi-Maskawa matrix elements V ud and V us.