Hidden strangeness in nucleons, magnetic moments and SU(3)

The role of nonvalence, e.g., sea quarks and/or meson degrees of freedom in static electroweak baryon observables is briefly discussed.Comment: 8 pages, Latex, no figures; prepared for Mini-Workshop on Hadron Structure with Quark Dynamics, Dec.8,2001, Kobe University, Kobe, Japan; FHD Proceedings, March 2002, Kobe University, Kobe, Japa

Hadron spectroscopy based on relativistic Schr\"odinger-like wave equations

Relativistic potential-type equations are proposed which approximately reproduce important features and constraints of field-theoretic models and can be useful tool in hadron spectroscopy. Within this approach, the Regge-trajectory parameters and some properties of hihger radial excitations in the light quark sector are discussed.Comment: 7 pages, Latex, no figures; Talk given at the NUPPAC'99, 13-17 November 1999, Cairo, Egyp

On Mesoatoms of the Deuterium and Possible Existence of Exotic Dibaryons

As a desirable supplement to the reaction $pp \to pp2\gamma$, proposed earlier (nucl-th/9712064 and references therein) to probe for the NN--decoupled dibaryon resonances we suggest to use for the same goal the radiative capture processes in mesoatoms of the deuterium which we consider to be especially feasible for further test and invesigation of possible low-lying exotic resonance states.Comment: LaTex, 5 pages, no figures; Talk at the International Workshop "Hadronic Atoms and Positronium in the Standard Model", Joint Institute for Nuclear Research, Dubna, Russia, May 26-31, 199

Quark-Hadron Duality in Photoabsorption Sum Rules and Two Photon Decays of Meson Resonances

The idea of quark-hadron duality is developed and applied to integral sum rules for the photoexcitation of meson resonances. Some applications of the presented approach in the light and heavy quark sectors are made, and the role of the scalar diquark cluster degrees of freedom in the radiative formation of light scalar mesons is discussed.Comment: 7 pages, Latex, no figures; Talk given at the 2nd International Symposium on the Gerasimov-Drell-Hearn Sum Rule and the Spin Structure of the Nucleon, Genova, Italy, July 3-6, 200

Photoabsorption sum rules and quark structure parameters of hadrons

Following the idea of the quark-hadron duality we present, within the constituent quark model approach, the relations between different bremsstrahlung-weihgted integrals of the nucleon resonance photoexcitation cross sections and correlation functions of the quark dipole moments in the nucleon ground state. These functions are of interest for checking detailed quark-configuration structure of the nucleon state vector. Some applications of this approach in meson sector are made and the role of meson degrees of freedom in the electromagnetic baryon observables is briefly discussed.Comment: LaTex, 8 pages, no figures; Talk at the International Conference "Hadron Structure 2000", Stara Lesna, High Tatra Mountains, Slovak Republic, 2-7 October 200

Radiative processes of nucleon interactions and possible existence of exotic dibaryons

The cross section of the reaction $pp \to pp \gamma \gamma$ is estimated and the exploration possibilities of this reaction to probe for a possible excitation of subnuclear degrees of freedom in two-nucleon systems, in particular, the production and decay of the NN-decoupled dibaryon resonances, are briefly discussed.Some arguments for and implications of the intermediate dibaryon resonance excitation are inferred from preliminary data on the two-photon yield and energy distribution observed by the DIBAR2$\gamma$ - Collaboration at the kinetic energy of the initial proton $T_{lab} \simeq 200 MeV$.Comment: 7 pages, Latex, no figures, Talk given at the 13th International Seminar "Relativistic Nuclear Physics and Quantum Chromodynamics", Dubna, 2-7 Sept. 1996, and at International Workshop "Symmetry and Spin", Prague, 24-30 August 199

On radiative widths and a pattern of quark-diquark-gluon configuration mixing in low-lying scalar mesons

The earlier suggested and developed idea of quark-hadron duality, underlying "bremsstrahlung-weighted" sum rules for total or polarized photon interaction cross sections, is applied to the description of excitation of light scalar mesons in gamma-gamma interactions. The emphasis is put on the discussion of a role of the scalar diquark cluster degrees of freedom in the radiative formation of light scalar mesons.Comment: 6 pages, espcrc2.sty, no figures; Talk given at the 12th International Conference "Selected Problems of Modern Physics", Dedicated to the 95th anniversary of the birth of D.I. Blokhintsev (1908-1979), Dubna, Russia, 8-11 June, 200

Electroweak moments of baryons and hidden strangeness of the nucleon

The phenomenological sum-rule-based approach is used to discuss the quark composition dependence of some static electroweak characteristics of baryons.The role of nonvalence degrees of freedom (the sea partons and/or peripheral meson currents) is shown to be important to select and make use of the relevant symmetry parametrization of baryon observables.The implications of the baryon magnetic moment analysis for estimation of the $\Delta$q values of the spin-dependent DIS on nucleons, the contribution of hidden strangeness to the nucleon magnetic moment and to the quark-line-rule violating $\phi \pi$ - production in antinucleon-nucleon annihilation reaction are presented.Comment: LaTex, 8 pages, no figures; talk given at the 2nd ELFE Workshop on Hadronic Physics, Saint Malo, France, 23-27 September, 1996; the abstract is slightly enlarged compared with the journal versio

On Valence Gluons in Heavy Quarkonia

To include the explicit valence gluon degrees of freedom into spectroscopy of the lowest states of heavy quarkonia, we consider, within an adiabatic model, the properties of the lowest hybrid $\bar{Q}Qg$-mesons and estimate the effects of their mixing with low-lying vector $\bar{c}c$-charmonia. The perspectives of compatibility of the resulting picture with data are discussed.Comment: LaTex, 5 pages, no figures; Talk at the XIth International Conference on Problems of Quantum Field Theory, dedicated to 90th anniversary of Professor D.I. Blokhintsev, Joint Institute for Nuclear Research, Dubna, Russia, July 13-17, 199

Further remarks on electroweak moments of baryons and manifestations of broken SU(3)

The role of nonvalence, {\it e.g.} sea quarks and/or meson degrees of freedom in static and quasistatic baryon electroweak observables, is discussed within the phenomenological sum rule approach. The inclusion of nonvalence degrees of freedom in the analysis of baryon magnetic moments explains extremely strong violation of the standard SU(6) symmetry-based quark-model prediction for the magnetic moment ratio $R_{\Sigma /\Lambda}=(\Sigma^{+} + 2\Sigma^{-})/(-\Lambda) \simeq .23$, while the value $R_{\Sigma /\Lambda}(SU(6))= 1$ corresponds to the nonrelativistic quark model. We also obtain $F/D=.72$ for the quark-current-baryon coupling $SU(3)_{f}$ ratio. The implications for the "strangeness" magnetism of the nucleon and for weak axial-to-vector coupling constant relations measured in the lowest octet baryon $\beta$-decays are discussed. The latter shows up the possible role of the induced second-class form factor (the "weak- electricity", or pseudotensor form factor) in the extraction of the $(g_1/f_1)$-values from the hyperon's $\beta$-decay data.Comment: 6 pages, LaTex, no figures; Talk at the Xth Advanced Research Workshop on High Energy Spin Physics (Dubna-SPIN-03), Sept. 16-20, 2003, Dubna, Russia; to appear in the Proceeding