Radiative vertex $VP\gamma$ and $\eta -{\eta }^{\prime }$ mixing in light-cone sum rules

Abstract

In this work, we calculate radiative vertex $VP\gamma$ ($V=\varphi ,\omega ,\rho$ and $P=\eta ,{\eta }^{\prime }$) by utilizing $\omega -\varphi$ mixing scheme and taking into account the contributions of the three-particle twist-4 distribution amplitudes of the photon in QCD sum rules on light cone. According to experimental data of $V\to P\gamma$ and $P\to V\gamma$ from PDG, a value of the $\eta -{\eta }^{\prime }$ mixing angle, $\varphi =(40.9\pm 0.5{)}^{\circ }$, is extracted in the framework of the quark-flavor basis to describe the $\eta -{\eta }^{\prime }$ system.

Comments: 9 pages, 12 figures, 2 tables