Newly observed ${\Lambda }_c(2860{)}^{+}$ at LHCb and its \emph{D}-wave partners ${\Lambda }_c(2880{)}^{+}$, ${\Xi }_c(3055{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$

Abstract

New resonance ${\Lambda }_c(2860{)}^{+}$, reported by LHCb, is a key to establish \emph{D}-wave charmed and charmed-strange baryon families. In this work, we first carry out an analysis of mass spectra of the $\lambda$-mode excited charmed and charmed-strange baryon states, which may reveal the relation of ${\Lambda }_c(2860{)}^{+}$, ${\Lambda }_c(2880{)}^{+}$, ${\Xi }_c(3055{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$, $i.e.$, ${\Lambda }_c(2860{)}^{+}$ and ${\Lambda }_c(2880{)}^{+}$ can form a \emph{D}-wave doublet $[3/2^{+},5/2^{+}]$ while ${\Xi }_c(3055{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$ are the strange partners of ${\Lambda }_c(2860{)}^{+}$ and ${\Lambda }_c(2880{)}^{+}$, respectively. Further study of their two-body Okubo-Zweig-Iizuka-allowed decays supports ${\Lambda }_c(2860{)}^{+}$ and ${\Xi }_c(3055{)}^{+}$ as the \emph{D}-wave charmed and charmed-strange baryons, respectively, with $J^P=3/2^{+}$. For ${\Lambda }_c(2880{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$, however, there exist some difficulties under the \emph{D}-wave assignment with $J^P=5/2^{+}$ since the experimental widths and some ratios of partial width of ${\Lambda }_c(2880{)}^{+}$ and ${\Xi }_c(3080{)}^{+}$ cannot be reproduced in our calculation.

Comments: 6 pages, 1 figures, 4 tables, RevTex, more discussions and references added, Accepted by Phys. Rev. D