Static properties and semileptonic decays of doubly heavy baryons in a nonrelativistic quark model

Abstract

We evaluate static properties and semileptonic decays for the ground state of doubly heavy $Ξ, Ξ', Ξ^*$ and $Ω, Ω', Ω^*$ baryons. Working in the framework of a nonrelativistic quark model, we solve the three--body problem by means of a variational ansazt made possible by heavy quark spin symmetry constraints. To check the dependence of our results on the inter-quark interaction we use five different quark-quark potentials that include a confining term plus Coulomb and hyperfine terms coming from one--gluon exchange. Our results for static properties (masses, charge and mass radii, magnetic moments...) are, with a few exceptions for the magnetic moments, in good agreement with a previous Faddeev calculation. Our much simpler wave functions are used to evaluate semileptonic decays of doubly heavy $Ξ,Ξ'(J=1/2)$ and $Ω, Ω'(J=1/2)$ baryons. Our results for the decay widths are in good agreement with calculations done within a relativistic quark model in the quark--diquark approximation.