Study of the decays ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\omega$

Abstract

Using $(27.12\pm 0.14)\times 10^8$ $\psi (3686)$ events collected with the BESIII detector, we present the first observation of the decays ${\chi }_{cJ}\to \Lambda \bar{\Lambda }\omega$, where $J=0,1,2$, with statistical significances of $11.7\sigma ,11.2\sigma$, and $11.8\sigma$. The branching fractions of these decays are determined to be $\mathcal{B}({\chi }_{c0}\to \Lambda \bar{\Lambda }\omega )=(2.37\pm 0.22\pm 0.23)\times 10^{-4}$, $\mathcal{B}({\chi }_{c1}\to \Lambda \bar{\Lambda }\omega )=(1.01\pm 0.10\pm 0.11)\times 10^{-4}$, and $\mathcal{B}({\chi }_{c2}\to \Lambda \bar{\Lambda }\omega )=(1.40\pm 0.13\pm 0.17)\times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. We observe no clear intermediate structures.

11 pages, 10 figures