The doubly heavy baryons

We present the results for the masses of the doubly heavy baryons $\Xi_{QQ'}$ and $\Omega_{Q'Q}$ where $Q,Q'=b,c$ obtained in the framework of the simple approximation within the nonperturbative string approach.Comment: 4 pages, 1 EPS fig., using espcrc2.sty package. Talk presented by I.M.Narodetskii at the 5th International Conference on Hyperon, Charm and Beauty Hadrons, Vancouver, Canada, June 200

Lifetimes of the b-flavored baryons in the light-front quark model

The calculation of lifetimes of heavy-flavored baryons in the light-front quark model approach is briefly reviewed.Comment: 4 pages, proceedings of the IV International Conference on Hyperons, Charm and Beauty Hadrons, Valencia, June 27--30, 200

Pentaquarks in string dynamics

The masses of $uudd\bar s$, $uudd\bar d$, and $uuss\bar d$ pentaquarks are evaluated in a framework of both the Effective Hamiltonian approach to QCD and spinless Salpeter using the Jaffe-Wilczek diquark approximation and the string interaction for the diquark-diquark-antiquark system. The masses of the light pentaquarks are found to be in the region above 2 GeV. The similar calculations yield the mass of $[ud]^2\bar c$ pentaquark $\sim$ 3250 MeV and $[ud]^2\bar b$ pentaquark $\sim$ 6509 MeV.Comment: 5 pages. Based on talk by I.M.Narodetskii at BEACH 2004, 6th International Conference on Hyperons, Charm and Beauty Hadrons, Illionois Institute of Technology, Chicago, June. 27 - July 3, 2004. Typos correcte

The general relation between the weak inclusive decays of bound and free heavy quarks

We derive a new parton formula for the inclusive B decays and briefly discuss its applications to semileptonic and weak radiative decays of the B-meson.Comment: espcrc2.sty (included), 3 pages, Presented at the Third International Conference on Hyperons, Charm and Beauty Hadrons, Genova, June 30 --July 3, 1998, to appear in proceeding

Accuracy of Auxiliary Field Approach for Baryons

We provide a check of the accuracy of the auxiliary field formalism used to derive the Effective Hamiltonian for baryons in the Field Correlator Method. To this end we compare the solutions for the Effective Hamiltonian with those obtained from the solution of the Salpeter equation. Comparing these results gives a first estimate of the systematic uncertainty due to the use of the auxiliary field formalism for baryons.Comment: 6 pages, 2 tables; published versio

The B_c Meson Lifetime in the Light--Front Constituent Quark Model

We present an investigation of the total decay rate of the (ground state) B_c meson within the framework of the relativistic constituent quark model formulated on the light-front (LF). The exclusive semileptonic (SL) and nonleptonic (NL) beauty and charm decays of the B_c meson are described through vector and axial hadronic form factors, which are calculated in terms of a constituent quark model LF wave functions. The latter ones are derived via the Hamiltonian LF formalism using as input the update versions of the constituent quark model. The inclusive SL and NL partial rates are calculated within a convolution approach inspired by the partonic model and involving the same B_c wave function which is used for evaluation of the exclusive modes. The framework incorporates systematically 84 exclusive and 44 inclusive partial rates corresponding to the underlying \bar{b}\to\bar{c} and c\to s quark decays. Based on our approach we find\tau_{B_c}=0.59 \pm 0.06 ps where the theoretical uncertainty is dominated by the uncertainty in the choice of LF wave functions and the threshold values for the hadron continuum. For the branching fractions of the B^+_c \to J/\psi\mu^+\nu_{\mu} and B_c^+\to J/\psi\pi^+ decays we obtain 1.6 % and 0.1 %, respectively.Comment: 10 pages, LaTeX, 1 ps figur

Pentaquark spectrum in string dynamics

The masses of $uudd\bar s$ and $uudd\bar d$ pentaquarks are evaluated in a framework of the Effective Hamiltonian approach to QCD using the Jaffe-Wilczek $[ud]^2\bar q$ approximation. The mass of the $[ud]^2\bar s$ state is found to be $\sim 300-500$ MeV higher than the observed $\Theta^+(1540)$ mass.Comment: 6 pages, 1 figure included, LaTeX2e; several references added; misprints corrected; to appear in Physics Letters

Charmed decays of the B-meson in the quark model

Exclusive and inclusive, semileptonic and non-leptonic, charmed decays of the B-meson are investigated in the context of a phenomenological quark model. Bound-state effects are taken care of by adopting a single (model-dependent) non-perturbative wave function, describing the motion of the light spectator quark in the B-meson. A nice reproduction of both exclusive and inclusive semileptonic data is obtained. Our predictions for the electron spectrum are presented and compared with those of the Isgur-Scora-Grinstein-Wise quark model. Finally, our approach is applied to the calculation of inclusive non-leptonic widths, obtaining a remarkable agreement with experimental findings.Comment: to appear in the Proc. of the 2^{nd} Int. Conf. on Hyperons, Charm and Beauty Hadrons, Montreal, Canada, 27-30 August 199

Auxiliary fields and hadron dynamics

The relations existing between the auxiliary field (einbein field) formalism and the spinless Salpeter equation are studied in the case of two particles with the same mass, interacting via a confining potential. The problem of non-orthogonality for radial excited states in the auxiliary field formalism is discussed and found to be non-crucial. It is shown that the classical equations of motion of the rotating string model, derived from the QCD lagrangian, reduce exactly to the classical equations of motion of the phenomenological semirelativistic flux tube model, provided all auxiliary fields are eliminated correctly from the rotating string hamiltonian

Inclusive pentaquark and strange baryons production in pp and \Sigma p collisions at high energy

We calculate the cross sections for the inclusive production in the fragmentation region of $\Theta^+(1540)$ and $\Lambda(1520)$ in $pp$ collisions and $\Lambda(1520)$ in $\Sigma p$ collisions at high energy using the $K$- and $\pi$-meson exchange diagrams, respectively. The contributions of these diagrams survive at asymptotically large energies and are energy independent in this region up to logarithmic and power corrections. We find that inclusive $\Theta^+(1540)$ production should be at the level of 1 $\mu\mathrm{b}\times\Gamma_{\Theta KN}/ 1$ MeV. The ratio of the $\Theta^+(1540)$ over the $\Lambda(1520)$ yields is found to be $\sim 1$. The fraction of $\Lambda(1520)$ yields in $\Sigma p$ and $pp$ collisions is $\sim 2.7$ that quantitatively agrees with the preliminary result of the Fermilab fixed target experiment E781.Comment: 5 pages, 5 figures, 1 table; RevTeX