Inelastic Hadron Diffraction in High Energy Elastic Scattering of Nuclei

Inelastic hadron diffraction refers to quasi-elastic transitions in which the colliding particles conserve their dominant quantum numbers. High energy of collision facilitates to satisfy the condition of coherence thus assuring that interaction does not change the character of the particles. High energy elastic scattering of hadrons is thus generally built of: i) elastic diffraction which results from a strong absorption connected to an opening of a variety of inelastic channels and by analogy to classical optics it can be described in terms of geometrical shapes of colliding particles; ii) inelastic diffraction which appears as a quantum phenomenon related to intrinsic structure of hadrons and has no classical analogy. It will be shown that elastic (classical or geometrical) diffraction is dominating at low momentum transfers, especially in the region of the forward peak. Instead, the inelastic (quantum or dynamical) diffraction is particularly important at high momentum transfers.