Strange mesonic transition form factor in the chiral constituent quark model

Abstract

The form factor $g_{\rho \pi}^{(S)}(Q^{2})$ of the strange vector current transition matrix element $<\rho| \bar{s}\gamma_\mus|\pi>$ is calculated within the chiral quark model. A strange vector current of the constituent $U$- and D-quarks is induced by kaon radiative corrections and this mechanism yields the nonvanishing values of $g_{\rho\pi}^{(S)}(0)$. The numerical result at the photon point is consistent with the one given by the $\phi $-meson dominance model, but the fall-off in the $Q^{2}$-dependence is faster than the monopole form factor. Mesonic radiative corrections are also examined for the electromagnetic $\rho $-to-$\pi $ and $K^{*}$-to-$K$ transition amplitudes.