Anatolii K. Likhoded

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.

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

The semileptonic B_c-meson decays into the heavy quarkonia J/\psi (\eta_c) and a pair of leptons are investigated in the framework of three-point sum rules of QCD and NRQCD. Calculations of analytical expressions for the spectral densities of QCD and NRQCD correlators with account for the Coulomb-like \alpha_s/v terms are presented. The generalized relations due to the spin symmetry of NRQCD for the form factors of B_c\to J/\psi (\eta_c)l\nu_l transitions with l denoting one of the leptons e, \mu or \tau, are derived at the recoil momentum close to zero. This allows one to express all NRQCD form factors through a single universal quantity, an analogue of Isgur-Wise function at the maximal invariant mass of lepton pair. The gluon condensate corrections to three-point functions are calculated both in full QCD in the Borel transform scheme and in NRQCD in the moment scheme. This enlarges the parameteric stability region of sum rule method, that makes the results of the approach to be more reliable. Numerical estimates of widths for the transitions of B_c\to J/\psi (\eta_c)l\nu_l are presented.Abstract The semileptonic Bc-meson decays into the heavy quarkonia J/ψ(ηc) and a pair of leptons are investigated in the framework of three-point sum rules of QCD and NRQCD. Calculations of analytical expressions for the spectral densities of QCD and NRQCD correlators with account for the Coulomb-like αs/v terms are presented. The generalized relations due to the spin symmetry of NRQCD for the form factors of Bc→J/ψ(ηc)lνl transitions with l denoting one of the leptons e,μ or τ, are derived at the recoil momentum close to zero. This allows one to express all NRQCD form factors through a single universal quantity, an analogue of Isgur–Wise function at the maximal invariant mass of lepton pair. The gluon condensate corrections to three-point functions are calculated both in full QCD in the Borel transform scheme and in NRQCD in the moment scheme. This enlarges the parameteric stability region of sum rule method that makes the results of the approach to be more reliable. Numerical estimates of widths for the transitions of Bc→J/ψ(ηc)lνl are presented.

Prospects for the Bc studies at LHCb

Motivations and perspectives for the studies of the mesons of the (bc) family at LHCb are discussed. The description of production and decays at LHC energies is given in detail. The event yields, detection efficiencies, and background conditions for several Bc decay modes at LHCb are estimated.

Physics of Bc-mesons

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

Physics of B(c) mesons

\bar b c

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

) 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 (

Double charmonium production in exclusive bottomonium decays

\bar b c

Lifetimes of

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

\Xi_{bc}^{+}

B_c^*

and

and pseudoscalar