Indication of change of phase in high-multiplicity proton-proton events at LHC in String Percolation Model

TL;DR

This paper investigates high-multiplicity proton-proton collisions at the LHC using the String Percolation Model, suggesting signs of a phase change similar to quark-gluon plasma formation, based on viscosity and degrees of freedom analysis.

Contribution

It applies the String Percolation Model to high-multiplicity $pp$ collisions, providing evidence for a phase transition akin to QGP formation in small systems.

Findings

Indications of a strongly interacting medium in $pp$ collisions.

Evidence of phase change signatures similar to QGP.

Analysis of viscosity and degrees of freedom supports collective behavior.

Abstract

We analyze high multiplicity proton-proton ($pp$) collision data in the framework of the String Percolation Model (SPM) that has been successful in describing several phenomena of multiparticle production, including the signatures of recent discovery of strongly interacting partonic matter, the Quark Gluon Plasma (QGP), in relativistic heavy-ion collisions. Our study in terms of the ratio of shear viscosity and entropy density ($\eta/s$) and the (LQCD) predicted signature of QCD change of phase, in terms of effective number of degrees of freedom ($\epsilon /T^4$), reiterates the possibility of strongly interacting collective medium in these events.