abstract

Assuming that the energy dependence of quasi on-shell parton–nucleon interactions can be parametrized in terms of J-plane singularities we explore consequences of Regge behavior for Deeply Virtual Compton Scattering (DVCS). In particular we find that resulting generalized parton distributions develop singularities which prevent the use of collinear factorization. The microscopic interpretation is that DVCS is dominated by photon dissociation into a quark–antiquark pair with subsequent re-scattering on target constituents rather than scattering on partons forming the target bound state.

abstract

Extended chiral sigma model with quark fields and elementary pion and sigma fields is used to describe static properties of the nucleon. The field equations have been solved in the coherent-pair approximation. Better results are obtained for the nucleon properties in comparison with previous work and reasonable agreement with data.

abstract

In this review, we first discuss the perspectives concerning a better determination of the proton structure in terms of quarks and gluons at LHC after describing the results coming from HERA and Tevatron. In a second part of the review, we describe the diffractive phenomena at HERA and Tevatron and the consequences for LHC.

abstract

Central diffractive production of heavy states (massive dijets, Higgs boson) is studied in the exclusive mode using a new Hybrid Pomeron Model. Built from Hybrid Pomerons defined by the combination of one hard and one soft color exchanges, the model describes well the centrally produced diffractive dijet data at the Tevatron. Predictions for the Higgs boson and dijet exclusive production at the LHC are presented.

abstract

The quasielastic \((p,\,n)\) reactions are studied for different incident proton energies. Transitions to isobaric analog states are obtained for different target nuclei with masses \(13 \leq A \leq 208\). The nucleon–nucleus interactions are considered to be density dependent in the optical model potential. Microscopic and macroscopic distorted-wave Born approximation (DWBA) calculations with the optical model potential are introduced. Differential cross-sections and angular distributions are calculated for different \((p,\,n)\) reactions. The present theoretical calculations are in good agreement with the experimental data.

abstract

In this paper we performed analyses of the data obtained of various ring-like events obtained from ultra relativistic nuclear interactions of \(^{32}\)S–AgBr at 200 \(A\)GeV, \(^{208}\)Pb–AgBr at 158 \(A\)GeV and \(^{197}\)Au–AgBr at 11.6 \(A\)GeV in the light of Cherenkov Radiation as proposed by Dremin. The refractive index of the nuclear medium is calculated from the knowledge of incident beam energy and cone angle of radiation. This study reveals values of the refractive index of the nuclear medium different from values of nuclear medium obtained for RHIC data.

abstract

An elementary pedagogical derivation of the Lense–Thirring precession is given based on the use of Hamilton vector. The Hamilton vector is an extra constant of motion of the Kepler/Coulomb problem related simply to the more popular Runge–Lenz vector. When a velocity-dependent Lorentz-like gravitomagnetic force is present, the Hamilton vector, as well as the canonical orbital momentum are no longer conserved and begin to precess. It is easy to calculate their precession rates, which are related to the Lense–Thirring precession of the orbit.