Semileptonic decays of heavy baryons in the relativistic quark model

Semileptonic decays of heavy baryons consisting of one heavy (Q=b,c) and two light (q=u,d,s) quarks are considered in the heavy-quark--light-diquark approximation. The relativistic quasipotential equation is used for obtaining masses and wave functions of both diquarks and baryons within the constituent quark model. The weak transition matrix elements are expressed through the overlap integrals of the baryon wave functions. The Isgur-Wise functions are determined in the whole accessible kinematic range. The exclusive semileptonic decay rates and different asymmetries are calculated with applying the heavy quark 1/m_Q expansion. The evaluated Lambda_b -> Lambda_c l nu decay rate agrees with its experimental value.Comment: 22 pages, 9 figure

Heavy baryon spectroscopy

Masses of heavy baryons are calculated in the relativistic quark-diquark picture. Obtained results are in good agreement with available experimental data including recent measurements by the LHCb Collaboration. Possible quantum numbers of excited heavy baryon states are discussed.Comment: 10 pages, 1 figure, talk at XXIV International Baldin Seminar on High Energy Physics Problems, Sep 17-22, 2018, Dubna, Russi

Semileptonic Ξc\Xi_c baryon decays in the relativistic quark model

The form factors of the weak $\Xi_c\to \Xi(\Lambda)$ transitions are calculated in the framework of the relativistic quark model based on the quasipotential approach. All relativistic effects including transformations of the baryon wave functions from the rest to moving reference frame and contributions of the intermediate negative energy states are systematically taken into account. The explicit analytic expressions which reliably approximate the momentum transfer $q^2$ dependence of the form factors in the whole accessible kinematical range are given. The calculated form factors are applied for the evaluation of the semileptonic $\Xi_c\to \Xi \ell\nu_\ell$ and $\Xi_c\to \Lambda \ell\nu_\ell$ ($\ell=e,\mu$) decay rates, different asymmetry and polarization parameters within helicity formalism. The obtained results are compared with available experimental data and previous calculations.Comment: 11 pages, 7 figures, v2: normalization of form factors corrected, extended discussion, published versio