Weak electric and magnetic form factors for semileptonic baryon decays in an independent-quark model.

Abstract

Weak electric and magnetic form factors for semileptonic baryon decays are calculated in a relativistic quark model based on the Dirac equation with the independent-quark confining potential of the form (1+${\ensuremath{\gamma}}^{0}$)V(r). The values obtained for (${g}_{2}$/${g}_{1}$), for various decay modes in a model with V(r)=a'${r}^{2}$, are roughly of the same order as those predicted in the MIT bag model. However in a similar model with V(r)=(${a}^{\ensuremath{\nu}+1}$${r}^{\ensuremath{\nu}}$+${V}_{0}$), the (${g}_{2}$/${g}_{1}$) values agree with the nonrelativistic results of Donoghue and Holstein. Incorporating phenomenologically the effect of nonzero ${g}_{2}$ in the ratio (${g}_{1}$/${f}_{1}$), we have estimated the values for (${f}_{2}$/${f}_{1}$) for various semileptonic transitions. It is observed that SU(3)-symmetry breaking does not generate significant departures in (${f}_{2}$/${f}_{1}$) values from the corresponding Cabibbo values.