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 $p{D}^0$ relative to ${\Sigma }_c(2455)\pi$

Abstract

We search for excited charmed baryons in the ${\Lambda }_c^{+}\eta$ system using a data sample corresponding to an integrated luminosity of 980 $\mathrm{f}{\mathrm{b}}^{-1}$. 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 $p{D}^0$ 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 $p{D}^0$ 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 ${\Lambda }_c(2940{)}^{+}$.

Comments: 10 pages, 4 figures, accepted for publication as a Regular Article in Physical Review D