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

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.

14 pages, 12 figures. Updated to mirror version accepted by journal

References in corpus (7)

• Viscosity Information from Relativistic Nuclear Collisions: How Perfect is the Fluid Observed at RHIC?
• Observation of long-range near-side angular correlations in proton-lead collisions at the LHC
• Evidence for collective multi-particle correlations in pPb collisions
• Thermal Hadronization and Hawking-Unruh Radiation in QCD
• Long-range two-particle correlations of strange hadrons with charged particles in pPb and PbPb collisions at LHC energies
• The Thermal Production of Strange and Non-Strange Hadrons in e+e- Collisions
• Observation of a "Ridge" correlation structure in high multiplicity proton-proton collisions: A brief review

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