Yu.A. Simonov

Vacuum Background Fields in QCD as a Source of Confinement

Abstract Quarks and gluons in the vacuum background field with a finite correlation length d are shown to be linearly confined inside white states. The string tension for an arbitrary representation of SU(N) is obtained in terms of d and the gluon condensate and agrees with numerical data and large N behaviour. The QCD string picture is shown to emerge asymptotically at large euclidean distances.

Nonperturbative dynamics of heavy quarkonia

Abstract In the confining background field method (CBFM) the non-perturbative quark-antiquark interaction is expressed via the bilocal vacuum correlators D (x 2 + τ 2 ) and D 1 (x 2 + τ 2 ) . The proper-time path-integral method of Schwinger and Feynman is used to derive systematically the nonrelativistic expansion of q q interaction including spin-dependent terms. The latter are very sensitive to D and D 1 . The potentials obtained reproduce main phenomenological features: confinement, scalar-exchange-type spin-orbit and short-range spin-spin interaction.

Gluelump spectrum in the QCD string model

Abstract The spectrum of gluons in the adjoint source field is computed analytically using the QCD string Hamiltonian, containing only one parameter — string tension, fixed by meson and glueball spectrum. Spin splitting is shown to be small. A good agreement is observed with specially generated gluelump states measured on the lattice. The important role of gluelumps defining the behaviour of field-strength correlators is stressed and correspondence with earlier computations of the latter is established.Spectrum of gluons in the adjoint source field is computed analytically using the QCD string Hamiltonian, containing only one parameter - string tension, fixed by meson and glueball spectrum. Spin splitting is shown to be small. A good agreement is observed with spatially generated gluelump states measured on the lattice. Important role of gluelumps defining the behaviour of field-strength correlators is stressed and correspondence with earlier computations of the latter is established.

Soliton-soliton interaction in confining models

Solitons in confining models of the Werle type are considered in one spatial dimension and the interaction between them is studied numerically in detail. In the collision process new localized objects are generated, which are pulsating in time. Evidence is given about their stability.

Ideas in non-perturbative QCD

The structure of the hadron spectrum is discussed in connection with the main phenomena of nonperturbative QCD: confinement and chiral symmetry breaking (CSB). For the higher part of the spectrum (

The nucleon-antinucleon interaction and resonances

M ge 2 GeV

On the structure of the πd amplitude neat the ΔN threshold

) spin and chiral effects are unimportant; spectrum of

Are there resonances in the πd system near the ΔN threshold

qbar{q}

Fermionic zero modes for dyons and chiral symmetry breaking in QCD

system is described by an effective Hamiltonian deduced from QCD. The Hamiltonian reduces to relativistic quark potential model or to the open string model in two opposite limits. Hybrids are shown to appear naturally in theory and enter the multiplets which are compared to experiment and bosonic string theory. The phenomenon of conspiracy of the spectrum of radial excited states producing operator product expansion is discussed. The lower part of the spectrum

The single-scattering contribution to πD elastic scattering at low and intermediate energies

(M<2 GeV)