Search for charmed baryons in the $\Lambda_c^+\eta$ system and measurement of the branching fractions of $\Lambda_c(2880)^+$ and $\Lambda_c(2940)^+$ decaying to $\Lambda_c^+\eta$ and $pD^0$ relative to $\Sigma_c(2455)\pi$

TL;DR

This study searches for excited charmed baryons in the $\Lambda_c^+\eta$ system, finds no significant signals there, but measures branching ratios for known states decaying into different channels, providing new limits and data.

Contribution

It provides the first upper limits on certain decay ratios of $\Lambda_c(2880)^+ ext{ and }\Lambda_c(2940)^+$ in the $\Lambda_c^+\eta$ channel and measures their branching fractions to $pD^0$ relative to $\Sigma_c(2455)\pi$.

Findings

No significant signals in $\Lambda_c^+\eta$ spectrum for known states.

Measured branching ratios for $\Lambda_c(2880)^+ ext{ and }\Lambda_c(2940)^+$ decaying to $pD^0$.

Set upper limits on decay ratios to $\Lambda_c^+\eta$ channel.

Abstract

We search for excited charmed baryons in the $\Lambda_c^+\eta$ system using a data sample corresponding to an integrated luminosity of 980 $\rm fb^{-1}$. The data were collected by the Belle detector at the KEKB $e^{+}$$e^{-}$ asymmetric-energy collider. No significant signals are found in the $\Lambda_c^+\eta$ mass spectrum, including the known $\Lambda_c(2880)^+$ and $\Lambda_c(2940)^+$. Clear $\Lambda_c(2880)^+$ and $\Lambda_c(2940)^+$ signals are observed in the $pD^0$ mass spectrum. We set upper limits at 90\% credibility level on ratios of branching fractions of $\Lambda_c(2880)^+$ and $\Lambda_c(2940)^+$ decaying to $\Lambda_c^+\eta$ relative to $\Sigma_c(2455)\pi$ of $<0.13$ for the $\Lambda_c(2880)^+$ and $<1.11$ for the $\Lambda_c(2940)^+$. We measure ratios of branching fractions of $\Lambda_c(2880)^+$ and $\Lambda_c(2940)^+$ decaying to $pD^0$ relative to $\Sigma_c(2455)\pi$ of $0.75 \pm 0.03(\text{stat.}) \pm 0.07(\text{syst.})$ for the $\Lambda_c(2880)^+$ and $3.59 \pm 0.21(\text{stat.}) \pm 0.56(\text{syst.})$ for the $\Lambda_c(2940)^+$.