Charmed strange pentaquarks in the large N_c limit

The properties of pentaquarks containing a heavy antiquark and strange quarks are studied in the bound state picture. In the flavor SU(3) limit, there are many pentaquark states with the same binding energy. When the SU(3) symmetry-breaking effects are included, however, three states become particularly stable due to a ‘‘Gell-Mann–Okubo mechanism.’’ They are the Q¯suud and Q¯sudd states discussed by Lipkin, and a previously unstudied Q¯ssud state. These states will have J^P=1/2⁺ and their masses are estimated. These states, if they exist, may be seen in experiments in the near future. © 1996 The American Physical Society.