The Study Of Heavy Baryons Semileptonic Decays And Rare Decays Using Light-cone Sum Rule

This paper mainly studies the application of the Light-Cone Sum Rule in the area of heavy baryon semileptonic decay?c? ?l?land rare decay ?b? ?? in the framework of complete QCD and HQET.The asymptotic freedom and color confinement of QCD determines that we must refer to the non-perturbative methods to resolve some problems of baryons in the lowenergy area. There are many QCD non-perturbative method, of which Light-cone Sum Rule deprived from SVZ sum rule is based on first principle of QCD and is very effective in solving the non-perturbative problems. Firstly we study heavy baryon semileptonic decay ?c? ?l?lform factors using Light-cone Sum Rule in the framework of conplete QCD, the heavy quark limit and HQET. We get the trend of form factors with the variation of threshold of continuum states and Borel parameter in the framework of complete QCD and HQCT. Comparing these two situation, we find there are few differences, indicating the reliability of our results and the important rule played by heavy quark symmetry on the heavy baryons.Then we study the rare decay ?b? ?? using the same method and the same pattern is obtained. The rare decay width and branching ratio is given at last. Our results are consistent with the predictions of other model.