The doubly heavy baryons in the nonperturbative QCD approach

We present some piloting calculations of the masses of the doubly heavy baryons in the framework of the simple approximation within the nonperturbative string approach. The simple analytical results for dynamical masses of heavy and light quarks and eigenvalues of the effective QCD Hamiltonian are presented.Comment: 4 pages; talk presented at the 9th International Conference on the Structure of Baryons (Baryons-2002), 3-8 March, 2002, Newport News, VA, US

Semirelativistic potential model for low-lying three-gluon glueballs

The three-gluon glueball states are studied with the generalization of a semirelativistic potential model giving good results for two-gluon glueballs. The Hamiltonian depends only on 3 parameters fixed on two-gluon glueball spectra: the strong coupling constant, the string tension, and a gluon size which removes singularities in the potential. The Casimir scaling determines the structure of the confinement. Low-lying $J^{PC}$ states are computed and compared with recent lattice calculations. A good agreement is found for $1^{--}$ and $3^{--}$ states, but our model predicts a $2^{--}$ state much higher in energy than the lattice result. The $0^{-+}$ mass is also computed.Comment: 2 figure

Ground-state baryons in nonperturbative quark dynamics

We review the results obtained in an Effective Hamiltonian (EH) approach for the three-quark systems. The EH is derived starting from the Feynman--Schwinger representation for the gauge-invariant Green function of the three quarks propagating in the nonperturbative QCD vacuum and assuming the minimal area law for the asymptotic of the Wilson loop. It furnishes the QCD consistent framework within which to study baryons. The EH has the form of the nonrelativistic three-quark Hamiltonian with the perturbative Coulomb-like and nonperturbative string interactions and the specific mass term. After outlining the approach, methods of calculations of the baryon eigenenergies and some simple applications are explained in details. With only two parameters: the string tension $\sigma=0.15 GeV^2$ and the strong coupling constant $\alpha_s=0.39$ a unified quantitative description of the ground state light and heavy baryons is achieved. The prediction of masses of the doubly heavy baryons not discovered yet are also given. In particular, a mass of $3660 MeV$ for the lightest $\Xi_{cc}$ baryon is found by employing the hyperspherical formalism to the three quark confining potential with the string junction.Comment: 25 pages, 4 figures included, LaTeX 2e; to be published in Phys. Atom. Nuc

Pentaquarks in the Jaffe-Wilczek approximation

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 pentaquark masses are found to be in the region above 2 GeV. That indicates that the Goldstone boson exchange effects may play an important role in the light pentaquarks. The same calculations yield the mass of $[ud]^2\bar c$ pentaquark $\sim$ 3250 MeV and $[ud]^2\bar b$ pentaquark $\sim$ 6509 MeV.Comment: 14 pages, 2 tables, LaTeX2e. References correcte

Baryons in the Field Correlator Method

The ground and $P$-wave excited states of $nnn$, $nns$ and $ssn$ baryons are studied in the framework of the field correlator method using the running strong coupling constant in the Coulomb-like part of the three-quark potential. The string correction for the confinement potential of the orbitally excited baryons, which is the leading contribution of the proper inertia of the rotating strings, is estimated.Comment: 6 pages, 2 figures. Talk given at APS April Meeting, Denver, Colorado, May 2-5, 2009 and at the Tenth Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2009), San Diego, California, May 26-31, 200