Geometrical scaling in high energy collisions and its breaking

TL;DR

This paper investigates geometrical scaling in high-energy collisions, demonstrating its validity up to certain Bjorken x values and identifying signs of scaling violations at higher x in various experiments.

Contribution

It provides a comparative analysis of geometrical scaling across different experiments and energies, highlighting where scaling holds and where it breaks down.

Findings

GS works up to Bjorken x ~ 0.1 in various experiments.

Scaling violations increase with rapidity at higher x values.

Clear signs of scaling breaking are observed at NA61/SHINE energies.

Abstract

We analyze geometrical scaling (GS) in Deep Inelstic Scattering at HERA and in pp collisions at the LHC energies and in NA61/SHINE experiment. We argue that GS is working up to relatively large Bjorken $x \sim 0.1$. This allows to study GS in negative pion multiplicity $p_{\rm T}$ distributions at NA61/SHINE energies where clear sign of scaling violations is seen with growing rapidity when one of the colliding partons has Bjorekn $x \ge 0.1$.