Observation of OZI suppressed decays ${\chi }_{cJ}\to \omega \varphi$

Abstract

Decays ${\chi }_{cJ}(J=0,1,2)\to \omega \varphi$ are studied using $(448.1\pm 2.9)\times 10^6\psi (3686)$ events collected with the BESIII detector in 2009 and 2012. In addition to the previously established ${\chi }_{c0}\to \omega \varphi$, first observation of ${\chi }_{c1}\to \omega \varphi$ is reported in this paper. The measured product branching fractions are $\mathcal{B}(\psi (3686)\to \gamma {\chi }_{c0})\times \mathcal{B}({\chi }_{c0}\to \omega \varphi )=(13.83\pm 0.70\pm 1.01)\times 10^{-6}$ and $\mathcal{B}(\psi (3686)\to \gamma {\chi }_{c1})\times \mathcal{B}({\chi }_{c1}\to \omega \varphi )=(2.67\pm 0.31\pm 0.27)\times 10^{-6}$, and the absolute branching fractions are $\mathcal{B}({\chi }_{c0}\to \omega \varphi )=(13.84\pm 0.70\pm 1.08)\times 10^{-5}$ and $\mathcal{B}({\chi }_{c1}\to \omega \varphi )=(2.80\pm 0.32\pm 0.30)\times 10^{-5}$. We also find a strong evidence for ${\chi }_{c2}\to \omega \varphi$ with a statistical significance of 4.8$\sigma$, and the corresponding product and absolute branching fractions are measured to be $\mathcal{B}(\psi (3686)\to \gamma {\chi }_{c2})\times \mathcal{B}({\chi }_{c2}\to \omega \varphi )=(0.91\pm 0.23\pm 0.12)\times 10^{-6}$ and $\mathcal{B}({\chi }_{c2}\to \omega \varphi )=(1.00\pm 0.25\pm 0.14)\times 10^{-5}$. Here, the first errors are statistical and the second ones systematic.

9 pages, 4 figures