Unitarisation dependence of diffractive scattering in light of high-energy collider data

We study the consequences of high-energy collider data on the best fits to total, elastic, inelastic, and single-diffractive cross sections for pp and $$ p\overline{p} $$ p p ¯ scattering using different unitarisation schemes. We find that the data are well fitted both by eikonal and U-matrix schemes, but that diffractive data prefer the U-matrix. Both schemes may be generalised by means of an additional parameter; however, this yields only marginal improvements to the fits. We provide estimates for ρ, the ratio of the real part to the imaginary part of the elastic amplitude, for the different fits. We comment on the effect of the different schemes on present and future cosmic ray data.

The elastic differential pp cross-section at 13 TeV: an empirical model analysis

We discuss the differential elastic pp cross-section data measured at 13 TeV, through the Coulomb Nuclear Interference region until past the dip. We show that data are consistent with the asymptotic predictions from an empirical model and examine the presence of a zero for the real part of the elastic amplitude near the Coulomb region, well before the dip.

Implications of the ρ(s) measurements by TOTEM at the LHC

Implications of the recent measurements of the parameter [Formula: see text] (ratio of the real to imaginary parts of the forward scattering elastic amplitude) by TOTEM collaboration at [Formula: see text] = 13 TeV are discussed with emphasis on the rising energy dependence of the ratio of elastic to total cross-sections.

INCLUSIVE PRODUCTION IN THE CENTRAL REGION: CONNECTION WITH THE ELASTIC AMPLITUDE

It is shown that on the basis of the two-reggeon approach, neglecting strong graphs and using three leading Regge singularities with Δ>0, Δ=0 and Δ<0, it is possible to have a good data description in wide intervals of energy and rapidities. This description is connected with that of the elastic amplitude.

MULTIPLE SCATTERING THEORY FOR INELASTIC PROCESSES

The review is devoted to the description of inelastic interactions of composite systems in the framework of the multiple scattering approach. Quasielastic scattering and multiple hadron production processes are considered for hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions at high energies. We show that important information on inelastic processes follows on very general grounds from the classification of various intermediate states in the elastic amplitude, as similarly AGK cutting rules arise for reggeon diagrams. Attention is mainly given to the appropriate technique, which is illustrated with several examples of increasing complexity. The general formalism for the inelastic screening corrections is presented and its particular applications to various reactions. The review does not aim at the systematic study of numerous versions of the multiple scattering calculus confronting each other and to the extensive experimental data. Instead, we concentrate on a few simple examples to make clear the underlying physics and to work out the needed machinery employed in practical calculations.