Collective Effects: the viewpoint of HEP MC codes

TL;DR

This paper reviews recent models explaining collective effects in high-multiplicity proton-proton collisions without relying on Quark Gluon Plasma formation, highlighting the lack of a unified theoretical framework.

Contribution

It analyzes various recent models that aim to explain collective effects in pp collisions without plasma formation, emphasizing the need for a unified approach.

Findings

Recent models partially explain collective effects in pp collisions.

Current models lack a unified theoretical framework.

Collective effects in pp resemble those in heavy ion collisions.

Abstract

Collective effects are observed in high-multiplicity pp events, similar to the signals traditionally attributed to the formation of a Quark Gluon Plasma in heavy ion collisions. In core--corona models it is assumed that a partial plasma formation is indeed possible also in pp, but here the focus is on several recent models that attempt to explain pp data without invoking plasma formation. These attempts are partly successful, but there is still not a unified framework.