Dynamical study of the pentaquark antidecuplet

Abstract

Dynamical 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 $uudd\bar{s}$, the mass of $Ξ^{--}$, of minimal content $ddss \bar{u}$, 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 kinetic energy plus the hyperfine interaction in this mixing is pointed out.

11 pages, espcrc1.sty, additional results on the octet-antidecuplet mixing and some numerical corrections to the published version in PLB595(2004)269-276. Conclusions unchanged