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

TL;DR

This paper investigates the decay process of Lambda_c into pi0, phi, and p, highlighting a triangle singularity mechanism that could produce observable peaks and exploring the potential existence of a hidden-strange pentaquark-like state.

Contribution

It introduces a novel triangle singularity mechanism in Lambda_c decay and assesses the possibility of a hidden-strange pentaquark-like state in this process.

Findings

A peak around 2020 MeV in the phi p invariant mass distribution.

Difficulty in detecting hidden-strange pentaquark-like states in this decay.

Predictions for nontrivial behavior in the phi p invariant mass distribution.

Abstract

We study the $\Lambda^+_c \to \pi^0 \phi p$ decay by considering a triangle singularity mechanism. In this mechanism, the $\Lambda^+_c$ decays into the $K^* \Sigma^*(1385)$, the $\Sigma^*(1385)$ decays into the $\pi^0 \Sigma$ (or $\Lambda$), and then the $K^* \Sigma$ (or $\Lambda$) interact to produce the $\phi p$ 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 $K^* \Lambda$, $K^* \Sigma$, and $\phi p$. 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 $\phi p$ invariant mass distribution. The predictions can be tested by experiments such as BESIII, LHCb and Belle-II.