Could the observation of $X(5568)$ be resulted by the near threshold   rescattering effects?
  We investigate the invariant mass distributions of $B_s\pi$ via different rescattering processes. Because the triangle singularity (TS) could be present for a very broad incident energy region, it can be expected that the TS peaks may simulate the resonance-like bump $X(5568)$ observed by the D0 collaboration. The highly process-dependent characteristic of TS mechanism offers a criterion to distinguish it from other dynamic mechanisms. 
Xiao-Hai Liu and Gang Li
hep-ph