Explore the properties of \(\Lambda (1670)\) in the Cabibbo-favored process \(\Lambda ^+_c \rightarrow p K^- \pi ^+\)

Abstract

Recently, the Belle and LHCb Collaborations have measured the \(\Lambda ^+_c \rightarrow p K^- \pi ^+\) decay and reported the \(K^- p\) invariant mass distribution, which shows a clear cusp structure around the \(\eta \Lambda \) threshold. In this work, we have analyzed this process by considering the triangle mechanism and the S-wave pseudoscalar meson-octet baryon interactions within the chiral unitary approach, which dynamically generates the \(\Lambda (1670)\). Our results are in good agreement with the Belle measurements, which implies that the cusp structure around \(\eta \Lambda \) threshold could be associated with the \(\Lambda (1670)\) with the molecular nature.