Proceedings: Workshop on Forward Physics and QCD at the LHC, the Future Electron Ion Collider, and Cosmic Ray Physics

Cristian Baldenegro ,D Delépine ,Martin Hentschinski ,C Royon

doi:10.17161/1808.30727

Abstract

These proceedings are the result of the fourth Workshop on Forward Physics and QCD at the LHC, the Future Electron Ion Collider, and Cosmic Ray Physics, held November 18-21 2019 in Guanajuato, Mexico. Previous meetings were held in Nagoya, Japan (2015, 2017), and Stony Brook, New York (2018).

Highlights

Recent measurements of the pp cross sections of the Auger and Large Hadron Collider (LHC) experiments[1, 2] had increased the interest in the discussions that the proton can develop asymptotically on a Black Bisk[3–5].The Geometric Scaling in the Froissart’s limit givesImF (s, t) = ImF (s, 0)φ(τ ), (1.1)where ImF (s, t) is the imaginary part of the amplitude and φ is the entire function of the scaling variable τ = −tσtot.One can separately describe the contributions of the imaginary part of the amplitude, one of the apparent growth of the hadron ’cross-sectional’ area with energy, R(s), and the other that modulates the gluonic saturation scale, f (s) that depends on energy
This description proposes that, based on the description of the geometric scaling, the cross section slowly evolves to the formation of a Black Disk as the energy in the center of collision mass increases and this growth is dominated by the function ∼ ln2(s) that dominates the imaginary part of the amplitude in the limit of saturation and that presents a modification in the saturation limit that changes due to the part distribution function, as shown in figure 2
It has the advantage that it separates the gluonic saturation function and allows the description of systems with the same apparent growth mediated by the R(s) function

Summary

Introduction

Where ImF (s, t) is the imaginary part of the amplitude and φ is the entire function of the scaling variable τ = −tσtot. One can separately describe the contributions of the imaginary part of the amplitude, one of the apparent growth of the hadron ’cross-sectional’ area with energy, R(s), and the other that modulates the gluonic saturation scale, f (s) that depends on energy. By following the optical theorem, one neglects the real part of the amplitude, the average of the imaginary part of the elastic amplitude is related to gluonic saturation scale, f (s): ImG(β) f (s), (1.2). Using the continuous partial wave approximation, one writes the transition amplitude in terms of an integral in the impact parameter space, from which the relations of the total and elastic crosssection are obtained as follows σtot = 2π db2ImG(s, b) = 2πR2(s)f (s),

Objectives

Methods

Results

Conclusion