Radiative transition processes of light vector resonances in a chiral framework

Within the framework of chiral effective field theory, we study various electromagnetic processes with light vector resonances: $K^{\ast}(892)\to K\gamma$,$e^{+}e^{-}\to K^{\ast}(892)K $andthe$\omega\pi\gamma^\ast$ form factors. With two multiplets of vector resonances being introduced, we fit the decay widths of $K^{\ast 0}\to K^0\gamma$, $K^{\ast +}\to K^{+}\gamma$, and the pertinent measurements from the $e^{+}{e}^{-}\to K^{\ast \pm }(892)K^{\mp }$ cross sections, such as moduli and relative phases between the isoscalar and isovector components from BABAR collaboration, together with the $\omega \pi$ form factors from NA60, SND and CLEO collaborations. The values of resonance couplings, masses and widths of the excited vector states ${\rho }^{\mathrm{\prime }}$ and ${\varphi }^{\mathrm{\prime }}$ are then determined. The ${\omega }^{\mathrm{\prime }}$-${\varphi }^{\mathrm{\prime }}$ mixing angle is discussed and turns out to be quite different from the ideal mixing case. Three sources of $SU(3)$ symmetry breaking effects in the $\mathrm{\Gamma }(K^{\ast }\to K\gamma )$ decays are identified and analyzed in detail.