Study of ${\chi }_{c0}(1P)-->J/\psi \gamma$ and ${\chi }_{b0}(1P)-->{\rm Y}(1S)\gamma$ decays via QCD sum rules

Abstract

In this study we present the first theoretical calculation of the form factor of the ${\chi }_{c0}(1P)\text{rar}J/\psi \gamma$ and ${\chi }_{b0}(1P)\to {\rm Y}(1S)\gamma$ decays in the frame work of QCD sum rules. We also find branching ratio ${\mathcal{B}}_r({\chi }_{c0}(1P)\to J/\psi \gamma )=(1.07\times \pm 0.14)\times 10^{(-2)}$ which is in agreement with the experimental data. Furthermore, we estimate the ${\Gamma }_{tot}({\chi }_{b0}(1P))=5.5\pm 0.5$ MeV, where experimental bound for full width of ${\chi }_{b0}$ is ${\Gamma }_{tot}({\chi }_{b0}(1P))<6$ MeV.

Comments: 7 pages, 2 figures