Triangular singularity and a possible $\varphi p$ resonance in the ${\Lambda }_c^{+}\to {\pi }^0\varphi p$ decay

Abstract

We study the ${\Lambda }_c^{+}\to {\pi }^0\varphi p$ decay by considering a triangle singularity mechanism. In this mechanism, the ${\Lambda }_c^{+}$ decays into the $K^{\ast }{\Sigma }^{\ast }(1385)$, the ${\Sigma }^{\ast }(1385)$ decays into the ${\pi }^0\Sigma$ (or $\Lambda$), and then the $K^{\ast }\Sigma$ (or $\Lambda$) interact to produce the $\varphi p$ in the final state. This mechanism produces a peak structure around $2020$ MeV. In addition, the possibility that there is a hidden-strange pentaquark-like state is also considered by taking into account the final state interactions of $K^{\ast }\Lambda$, $K^{\ast }\Sigma$, and $\varphi p$. We conclude that it is difficult to search for the hidden-strange analogue of the $P_c$ states in this decay. However, we do expect nontrivial behavior in the $\varphi p$ invariant mass distribution. The predictions can be tested by experiments such as BESIII, LHCb and Belle-II.

Comments: 7 pages, 3 figures