Five-flavor molecular pentaquarks in the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems

Abstract

The discovery of hidden-charm pentaquarks and open-flavor tetraquarks motivates the search for even more exotic hadron configurations. In this work, we investigate genuinely exotic molecular pentaquark candidates comprising five different flavors, focusing on the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems. Employing the one-boson-exchange model with the $S$-$D$ wave mixing and coupled-channel dynamics, we identify the most promising molecular pentaquark candidates comprising five different flavors. These include the ${\Xi }_b\bar{D}$, ${\Xi }_b^{\prime }\bar{D}$, ${\Xi }_{c}B$, and ${\Xi }_c^{\prime }B$ states with $I(J^P)=0(1/2^{-})$, the ${\Xi }_b{\bar{D}}^{\ast }$, ${\Xi }_b^{\prime }{\bar{D}}^{\ast }$, ${\Xi }_c{B}^{\ast }$, and ${\Xi }_c^{\prime }{B}^{\ast }$ states with $I(J^P)=0(1/2^{-},3/2^{-})$, the ${\Xi }_b^{\ast }\bar{D}$ and ${\Xi }_c^{\ast }B$ states with $I(J^P)=0(3/2^{-})$, as well as the ${\Xi }_b^{\ast }{\bar{D}}^{\ast }$ and ${\Xi }_c^{\ast }{B}^{\ast }$ states with $I(J^P)=0(1/2^{-},3/2^{-},5/2^{-})$. Importantly, these loosely bound states exhibit pronounced spin splittings across different total angular momentum configurations after incorporating the spin-dependent interactions or the channel couplings. In addition, we identify several possible isovector molecular pentaquark candidates within the ${\Xi }_b^{(\prime ,\ast )}{\bar{D}}^{(\ast )}$ and ${\Xi }_c^{(\prime ,\ast )}{B}^{(\ast )}$ systems. Our predictions provide clear targets for experimental searches at facilities such as LHCb and Belle II, where the unique five-flavor quark configuration offers a distinctive experimental signature.

Comments: 15 pages, 2 figures, and 8 tables