Choice of heavy baryon currents in QCD sum rules

Abstract

In this paper we investigate the effects due to the mixing of two interpolating currents for ground state baryons within the framework of Heavy Quark Effective Theory using the QCD sum rule approach. Both two-point and three-point sum rules, thus the mass, coupling constant and Isgur-Wise function sum rules are considered. It is interesting to contrast those results with each other. Based on the Isgur-Wise functions obtained in this paper, we also analyze the effects of current mixing to Lambda-type and and Sigma-type semi-leptonic decays Lambda_b-->Lambda_c\ell\bar\nu, \Sigma_b-->\Sigma_c\ell\bar\nu and \Sigma_b-->\Sigma^*_c\ell\bar\nu. Decay widths corresponding to various mixing parameters are obtained and can be compared to the experimental data.