Weak decay of Lambda_c^+ for the study of Lambda(1405) and Lambda(1670)

TL;DR

This paper investigates Lambda_c^+ decays into meson-baryon states to analyze Lambda resonances, demonstrating that such decays can isolate I=0 states and reveal features of Lambda(1405) and Lambda(1670) through chiral unitary calculations.

Contribution

It introduces Lambda_c^+ decay as an ideal process to study Lambda resonances, effectively isolating I=0 states and analyzing resonance structures via final state interactions.

Findings

PiSigma mass distributions show consistent peak structures related to Lambda(1405)

Clear Lambda(1670) peaks observed in KbarN and etaLambda spectra

Decay process suppresses I=1 contamination, aiding resonance analysis

Abstract

We study the Lambda_c decay process to pi^+ and the meson-baryon final state for the analysis of Lambda resonances. Considering the Cabibbo-Kobayashi-Maskawa matrix, color suppression, diquark correlation and the kinematical condition, we show that the final meson-baryon state should be in a pure I=0 combination, when the meson-baryon invariant mass is small. Because the I=1 contamination usually makes it difficult to analyze Lambda resonances directly from experiments, the Lambda_c decay is an ideal process to study Lambda resonances. Calculating the final state interaction by chiral unitary approaches, we find that the piSigma invariant mass distributions have the same peak structure in the all charge combination of the piSigma states related to the higher pole of the two poles of the Lambda(1405). Furthermore, we obtain a clear the Lambda(1670) peak structure in the KbarN and etaLambda spectra.