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 $\hat{I}ž,\hat{I}{ž}^{\prime },\hat{I}{ž}^{\ast }$ and $\hat{I}\text{c◯},\hat{I}{\text{c◯}}^{\prime },\hat{I}{\text{c◯}}^{\ast }$ 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 $\hat{I}ž,\hat{I}{ž}^{\prime }(J=1/2)$ and $\hat{I}\text{c◯},\hat{I}{\text{c◯}}^{\prime }(J=1/2)$ baryons. Our results for the decay widths are in good agreement with calculations done within a relativistic quark model in the quark--diquark approximation.

23 latex pages, 7 figures, 11 tables. Corrected version according to the discussion in the erratum to be published in Eur. Phys. J. A. Eur. Phys. J. A 32, 183 (2007); erratum Eur. Phys. J. A in press, available as online first