Molecular charmed baryons and pentaquarks from light-meson exchange saturation

Abstract

The spectrum of the $cqq$ baryons contains a few states whose nature is not clearly a three-quark composite and which might have a sizable baryon-meson component. Examples include the ${\Sigma }_c(2800)$ or the ${\Lambda }_c(2940)$. Here we explore the spectrum of two-body systems composed of a light, octet baryon and a charmed meson (or antimeson) within a simple contact-range theory in which the couplings are saturated by light-meson exchanges. This results in the prediction of a series of composite anticharmed pentaquarks ($\bar{c}qqqq$) and singly-charmed baryons ($c\bar{q}qqq$). Among the later we find $J=\frac{1}{2}$ $\Xi D$ and $J=\frac{3}{2}$ $\Xi D^{\ast }$ bound states with masses matching those of the recently observed ${\Omega }_c(3185)$ and ${\Omega }_c(3327)$ baryons.

Comments: 14 pages, 6 tables, corresponds to published version