Geometrical scaling in high energy collisions and its breaking

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 $x \ge 0.1$.