Thermal radiation and entanglement in proton-proton collisions at the LHC

TL;DR

This paper investigates the origin of thermalization in high-energy proton-proton collisions at the LHC, analyzing various processes to explore the relationship between temperature, scattering scale, and quantum entanglement.

Contribution

It extends the observed relation between effective temperature and hard scattering scale to Higgs production and examines the disappearance of thermal components in diffractive events.

Findings

Effective temperature relates to the hard scattering scale.

Thermal component vanishes in diffractive events.

The relation extends to Higgs boson production.

Abstract

The origin of the apparent thermalization in high-energy collisions is investigated using the data of the ATLAS and CMS Collaborations at the LHC. For this purpose, we analyze the transverse momentum distributions in the following proton-proton collision processes, all at $\sqrt{s} = 13$ TeV: i) inclusive inelastic $pp$ collisions; ii) single- and double-diffractive Drell-Yan production $pp \to \mu^+ \mu^- X$; and iii) Higgs boson production. We confirm the relation between the effective temperature and the hard scattering scale observed at lower energies, and find that it extends even to the Higgs boson production process. In addition we find that the thermal component disappears in diffractive events (even though many charged hadrons are still produced). We discuss the implications of our study for the mechanism of multi-particle production -- in particular, we test the hypothesis about the link between quantum entanglement and thermalization in high-energy collisions.