Novel observables for exploring QCD collective evolution and quantum entanglement within individual jets

TL;DR

This paper proposes novel observables to investigate collective effects and quantum entanglement in individual jets from high-energy collisions, aiming to deepen understanding of non-perturbative QCD dynamics at small scales.

Contribution

It introduces new observables for studying collective phenomena and quantum entanglement in jet fragmentation, using PYTHIA simulations to explore their potential signatures.

Findings

Identification of potential signatures of collectivity in high multiplicity jets

Insights into the role of quantum entanglement in thermal-like particle production

Proposals for experimental searches in high-energy elementary collisions

Abstract

We postulate that non-perturbative QCD effects occurring during parton fragmentation can result in collective effects of a multi-parton system, reminiscent of those observed in high-energy hadronic or nuclear interactions with large final-state particle multiplicity. Proton-proton collisions at the Large Hadron Collider showed surprising signatures of a strongly interacting, thermalized quark-gluon plasma, which was thought only to form in collisions of large nuclear systems. Another puzzle observed earlier in $e^{+}e^{-}$ collisions is that production yields of various hadron species appear to follow a thermal-like distribution with a common temperature. We propose searches for thermal and collective properties resulting from parton fragmentation processes using high multiplicity jets in high-energy elementary collisions. Several novel observables are studied using the PYTHIA 8 Monte Carlo event generator. Experimental observation of such collectivity will offer a new view of non-perturbative QCD dynamics of multi-parton systems at the smallest scales. Absence of any collective effects may offer new insights into the role of quantum entanglement in the observed thermal behavior of particle production in high energy collisions.