Pion-assisted charmed dibaryon candidate

Abstract

The ${\mathrm{\ensuremath{\Lambda}}}_{c}(2286)N$ system is studied in a chiral constituent quark model, and the resulting $s$-wave interaction is used in separable form within three-body models of the $\ensuremath{\pi}{\mathrm{\ensuremath{\Lambda}}}_{c}N$ system with quantum numbers $(C,I,{J}^{P})=(+1,\frac{3}{2},{2}^{+})$. Separable interactions are also used for the dominant $p$-wave pion-baryon channels dominated by the $\mathrm{\ensuremath{\Delta}}(1232)$ and ${\mathrm{\ensuremath{\Sigma}}}_{c}(2520)$ resonances. Faddeev equations with relativistic kinematics are solved on the real axis to search for bound states and in the complex plane to search for three-body resonances. Some of the models considered generate a very narrow bound state, requiring isospin violation for its strong decay. Other models lead to a narrow resonance ($\mathrm{\ensuremath{\Gamma}}\ensuremath{\lesssim}0.4\text{ }\text{ }\mathrm{MeV}$) for a resonance mass below the ${\mathrm{\ensuremath{\Sigma}}}_{c}(2455)N$ threshold. This would be the lowest-lying $C=+1$ dibaryon, with mass estimated as $\ensuremath{\approx}3370\ifmmode\pm\else\textpm\fi{}15\text{ }\text{ }\mathrm{MeV}$.