V. V. Kiselev

Bc decays and lifetime in QCD sum rules

In the framework of three-point QCD sum rules, the form factors for the semileptonic decays of B_c -->B_s(B_s^*) l \nu are calculated with account for the Coulomb-like alpha_s/v-corrections in the heavy quarkonium. The generalized relations due to the spin symmetry of HQET/NRQCD for the form factors are derived at the recoil momentum close to zero. The nonleptonic decays are studied using the assumption on the factorization. The B_c meson lifetime is estimated by summing up the dominating exclusive modes in the c -->s transition combining the current calculations with the previous analysis of b -->c decays in the sum rules of QCD and NRQCD.In the framework of three-point QCD sum rules, the form factors for the semileptonic decays of Bc+→Bs(Bs∗)l+νl are calculated with account for the Coulomb-like αs/v -corrections in the heavy quarkonium. The generalized relations due to the spin symmetry of HQET / NRQCD for the form factors are derived at the recoil momentum close to zero. The nonleptonic decays are studied using the assumption on the factorization. The Bc -meson lifetime is estimated by summing up the dominating exclusive modes in the c→s transition combining the current calculations with the previous analysis of b→c decays in the sum rules of QCD and NRQCD.

Baryons with two heavy quarks

We consider general physical characteristics of doubly heavy baryons: the spectroscopy in the framework of potential approach and sum rules of QCD, mechanisms of production in various interactions on the basis of fragmentation model with account of preasymptotic corrections caused by higher twists over the transverse momentum of baryon, inclusive decays and lifetimes in the operator product expansion over the inverse powers of heavy quark masses as well as the exclusive decays in the sum rules of QCD. We generalize the methods developed in the effective theory of heavy quarks towards the description of systems with two heavy quarks and a single light quark. The calculations are presented for the masses, decay widths and yields of baryons with two heavy quarks in the running and planned experimental facilities. We discuss the prospects of search for the baryons and possibilities of experimental observation. The most bright physical effects concerning these baryons as well as their position in the system for the theoretical description of heavy quark dynamics are considered.

B(c) spectroscopy

In the framework of potential models for heavy quarkonium the mass spectrum for the system (

Semileptonic Bc-meson decays in sum rules of QCD and NRQCD

\bar b c

Doubly charmed baryon production in hadronic experiments

) is considered. Spin-dependent splittings, taking into account a change of a constant for effective Coulomb interaction between the quarks, and widths of radiative transitions between the (

Physics of Bc-mesons

\bar b c

Physics of B(c) mesons

) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector

Lifetimes of doubly charmed baryons: Xi(cc)+ and Xi(cc)++

B_c^*

Heavy quark potential in the static limit of QCD

and pseudoscalar

Bc and\(b\bar bc\bar c\) at theZ0-boson pole

B_c