Generating a resonance-like structure in the reaction $B_c\to B_s\pi \pi$

Abstract

We investigate the process $B_c^{+}\to B_s^0{\pi }^{+}{\pi }^0$ via $B{\bar{K}}^{\ast }$ rescattering. The kinematic conditions for triangle singularities are perfectly satisfied in the rescattering diagrams. A resonance-like structure around the $B\bar{K}$ threshold, which we denote as $X(5777)$, is predicted to be present in the invariant mass distribution of $B_s^0{\pi }^{+}$. Because the relative weak $B\bar{K}$ $(I=1)$ interaction does not support the existence of a dynamically generated hadronic molecule, the $X(5777)$ can be identified as a pure kinematical effect due to the triangle singularity. Its observation may help to establish a non-resonance interpretation for some $XYZ$ particles.

Comments: 5 pages, 3 figures