Centrality in small systems at the LHC energies and beyond

TL;DR

This paper discusses the applicability of the centrality variable, used in nucleus-nucleus collisions, to classify small system events like proton-proton collisions at LHC energies, considering existing measurements and high-energy limits.

Contribution

It analyzes the relevance and potential limitations of using centrality classification in small systems at high energies, extending concepts from heavy-ion physics.

Findings

Centrality can be a useful classification in small systems.

Limitations arise at asymptotical energy regions.

Existing measurements support the relevance of centrality in small systems.

Abstract

Experimental observations at the LHC of the collective effects in small systems such as $pp$--scattering suggest introduction of the centrality variable to classify collision events similar to the case of nucleus--nucleus collisions. We discuss this issue with reference to the existing measurements at the LHC and the asymptotical energy region.