L. A. Kondratyuk

Suppression of nucleon resonances in the total photoabsorption on nuclei

Abstract We analyze the recent nuclear-photoabsorption data which have shown the disappearance on nuclei of the resonances higher than the Δ. We discuss how the Fermi motion, the collision broadening, and the Pauli blocking might distort the shape of nucleon resonances in the nuclear medium, and show that the Fermi motion and the collision broadening play the major role. From a fit to the photoabsorption data on uranium we have estimated the total cross sections for scattering of the resonances P 33 (1232), D 13 (1520), F 15 (1680), and D 33 (1700) on nucleons. The estimate for the P 33 -resonance cross section is in fair agreement with the value derived from the NN → Δ N cross sections, while those for the other resonances are high although do not violate the unitary limits.

Deuteron photodisintegration within the Quark-Gluon Strings Model and QCD motivated nonlinear Regge trajectories

Abstract:We investigate deuteron two-body photodisintegration within the framework of the Quark-Gluon Strings Model with nonlinear baryon Regge trajectories. Special attention is paid to the use of QCD motivated Regge trajectories of the logarithmic and square-root form. We find that the recent experimental data from TJNAF in the few-GeV region can be reasonably described by the model. Angular distributions at different γ-energies are presented and the effect of a forward-backward asymmetry is discussed. Predictions for the energy dependence of dσ/dt at higher energies and different Θc.m. are presented, too.

Forward-backward angle asymmetry and polarization observables in high-energy deuteron photodisintegration

Abstract.Deuteron two-body photodisintegration is analysed within the framework of the Quark-Gluon Strings Model. It is found that the forward-backward angle asymmetry predicted by the model is confirmed by the recent data at different photon energies from JLab. New calculations for polarization observables, the cross-section asymmetry

Near-threshold production of a0(980)-mesons in the reaction \(\rm {pp \rightarrow d K^ + \bar{K^0}}\)

\Sigma

Polarization observables in high-energy deuteron photo- disintegration within the Quark-Gluon Strings Model

and the polarization transfer

The K- alpha scattering length and the reaction dd ---> alpha K+ K-

C_{z^{\prime}}

Near-threshold production of a 0(980) mesons in πN and NN collisions and a 0-f 0 mixing

, for photon energies

a 0 + (980)-resonance production in the reaction pp → dπ+η close to the \(K\bar K\) threshold

(1.2\mbox{--}6)

The K- alpha scattering length and the reaction dd->alphaK-K+

GeV are presented and compared with the data available up to 2 GeV.

The K-α scattering length and the reaction dd → αK+K-

Abstract.Using an effective Lagrangian approach as well as the Quark-Gluon Strings Model, we analyze near-threshold production of a0(980)-mesons in the reaction