Interpretation of the measurements of total, elastic and diffractive cross sections at LHC

TL;DR

This paper analyzes recent LHC measurements of total, elastic, and diffractive cross sections in proton-proton collisions, comparing them with theoretical models and discussing the challenges in interpreting the data.

Contribution

It provides a detailed interpretation of LHC cross section measurements using eikonal models and highlights the difficulties in achieving a consistent theoretical understanding.

Findings

Total cross section matches (  )^2 prediction

Elastic cross section is lower than most expectations

The combined elastic and diffractive ratio approaches the theoretical maximum of 1/2

Abstract

Recently at LHC one has obtained measurements of the total, elastic and diffractive cross sections in pp collisions at very high energy. The total cross section is in good agreement with predictions based on a leading behavior \sigma_{tot} (s) \propto (\ln s/s_0)^2, on the other hand the elastic cross section is lower than most expectations and the diffractive cross section is higher. It is remarkable that the ratio (\sigma_{el} + \sigma_{diff})/\sigma_{tot} calculated combining the results of the TOTEM and ALICE detectors is 0.495^{+0.05}_{-0.06}, very close to the maximum theoretically allowed value of 1/2 known as the Miettinen Pumplin bound. In this work we discuss these results using the frameworks of single and multi--channel eikonal models, and outline the main difficulties for a consistent interpretation of the data.