Dynamical study of the pentaquark antidecuplet

AbstractDynamical calculations are performed for all isomultiplets of the flavour antidecuplet to which the newly discovered pentaquark Θ+ belongs. The framework is a constituent quark model where the short-range interaction has a flavour–spin structure. In this model the lowest pentaquarks have positive parity. Each antidecuplet member is described by a variational solution with the Pauli principle properly taken into account. By fitting the mass of Θ+ of minimal content uudds̄, the mass of Ξ−−, of minimal content ddssū, is predicted at approximately 1960 MeV. The influence of the octet-antidecuplet mixing on the masses of the Y=1 and 0 pentaquarks is considered within the same model and the role of the hyperfine interaction in this mixing is pointed out