Relativistic description of the charmonium mass spectrum

The charmonium mass spectrum is considered in the framework of the constituent quark model with the relativistic treatment of the c quark. The obtained masses are in good agreement with the existing experimental data including the mass of eta_c(2S).Comment: 5 page

Charm mass corrections to the bottomonium mass spectrum

The one-loop corrections to the bottomonium mass spectrum due to the finite charm mass are evaluated in the framework of the relativistic quark model. The obtained corrections are compared with the results of perturbative QCD.Comment: 6 pages, references added, version to be published in Phys. Rev.

Masses of light tetraquarks and scalar mesons in the relativistic quark model

Masses of the ground state light tetraquarks are dynamically calculated in the framework of the relativistic diquark-antidiquark picture. The internal structure of the diquark is taken into account by calculating the form factor of the diquark-gluon interaction in terms of the overlap integral of the diquark wave functions. It is found that scalar mesons with masses below 1 GeV: f_0(600) (\sigma), K^*_0(800) (\kappa), f_0(980) and a_0(980) agree well with the light tetraquark interpretation.Comment: 9 pages, Report-no adde

Heavy quark potential and mass spectra of heavy mesons

The relativistic quark model is presented. The quark-antiquark potential for the Schroedinger-like equation is constructed with the account of retardation effects and one-loop radiative corrections. It consists of the one-gluon exchange part and the confining part which is the mixture of the Lorentz scalar and Lorentz vector contributions. The latter contains both the Dirac and Pauli terms. In the v^2/c^2 approximation the mass spectra of heavy quarkonia (charmonium and bottomonium) are calculated in good agreement with experiment. In the case of heavy-light mesons (B and D) the light quark is treated completely relativistically and only the expansion in the inverse heavy quark mass is used. The mass spectra of the ground and excited states of D, D_s, B, B_s mesons are calculated. They exhibit some features of the so-called ``level inversion''. The obtained results are generally in accord with experimental data. Still there exist some discrepancies between measurements of different collaborations.Comment: 10 pages, plenary talk at the IXth International Conference on Hadron Spectroscopy (August 25-September 1, 2001) - HADRON 2001, Protvino, Russi

Heavy quarkonium hyperfine structure and leptonic decays

The relation between the hyperfine structure and leptonic decay rates of heavy quarkonia is considered with the account of relativistic and radiative corrections. The calculated decay rates agree well with the available experimental data, while the predicted eta_c(2S) mass is significantly smaller than the value measured recently by the Belle and BaBar Collaborations.Comment: Invited talk at the XXIII Physics in Collisions Conference (PIC03), Zeuthen, Germany, June 2003, 3 pages, LaTeX. PSN FRAP0

Hyperfine splitting and leptonic decay rates in heavy quarkonia

The hyperfine splitting in heavy quarkonia is considered in its relation to the leptonic decay rates with the account of relativistic and radiative corrections. The calculated decay rates agree well with the available experimental data, while the predicted \eta_c(2S) mass is significantly smaller than the value measured recently by the Belle Collaboration.Comment: 4 pages, misprint in Table 2 correcte