Production of $Z_{cs}$ in $B$ and $B_s$ decay

Abstract

In the present work, we investigate the production of $Z_{cs}^{+}$ in $B^{+}$ and $B_s^0$ decay, where $Z_{cs}^{+}$ is assigned as a $D_s^{+}{\bar{D}}^{\ast 0}+D_s^{\ast +}{\bar{D}}^0$ molecular state. By using an effective Lagrangian approach, we evaluate the branching ratio of $B_s^0\to K^{-}{Z}_{cs}^{+}$ and $B^{+}\to \varphi Z_{cs}^{+}$ via the triangle loop mechanism. The estimated branching fractions of $B_s^0\to K^{-}{Z}_{cs}^{+}$ and $B^{+}\to \varphi Z_{cs}^{+}$ are an order of $10^{-4}$ and $10^{-5}$, respectively. The ratio of these two branching fraction is estimated to be about 5, which indicate that the $B_s^0\to K^{\pm }{Z}_{cs}^{\mp }\to K^{+}{K}^{-}J/\psi$ may be a better process of searching $Z_{cs}$ and accessible for further experimental measurement of the Belle II and LHCb collaborations.

Comments: 8 pages, 3 figures