No Arabic abstract
This paper presents a qualitative explanation for the hollowness effect based on the inelastic overlap function, claiming this result is a consequence of fundamental thermodynamic processes. Using the Tsallis entropy, one identifies the entropic index $w$ with the ratio of the collision energy to critical one in the total cross-section. The integrated probability density function is replaced by the inelastic overlap function, which represents the probability of occurrence of an inelastic event depending on both the collision energy and impact parameter. The Coulomb potential, as well as the confinement potential, are used as naive approaches to describe the (internal) energy of the colliding hadrons. The Coulomb potential in the impact parameter picture is not able to furnish any reliable physical result near the forward direction. However, the confinement potential in the impact parameter space results in the hollowness effect shown by the inelastic overlap function near the forward direction.
The commonly used West and Yennie model approach to the description of the interference between Coulomb and hadronic scattering of nucleons is critically examined and its deficiencies are clarified. The preference of the more general eikonal model approach is summarized.
The ratio of elastic to total proton cross sections is related to the darkness of the spatial profile of inelastic interactions by a single parameter in the framework of a simple analytical model. Their critical values at LHC energies are discussed. Two possible variants of their asymptotical behavior are described.
A method of determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton and proton-nuclei elastic scattering at small momentum transfer. The method allows to decrease the number of model assumptions, to obtain the real parts of the spin non-flip and spin-flip amplitudes in the narrow region of momentum transfer.
We discuss some nuclear effects, RPA correlations and 2p2h (multinucleon) mechanisms, on charged-current neutrino-nucleus reactions that do not produce a pion in the final state. We study a wide range of neutrino energies, from few hundreds of MeV up to 10 GeV. We also examine the influence of 2p2h mechanisms on the neutrino energy reconstruction.
We use chiral perturbation theory to evaluate the scattering amplitude for the process Pi^+ K^- to Pi^+ K^- at leading and next-to-leading orders in the chiral counting and in the presence of isospin breaking effects. We also discuss the influence of the latter on the combination of the S-wave Pi K scattering lengths which is relevant for the 2S - 2P energy levels shift of K Pi atoms.