New picture of jet quenching dictated by color coherence

TL;DR

This paper introduces a new model of jet quenching based on color coherence and a jet resolution scale, explaining how high-energy jets lose energy coherently in nuclear collisions, consistent with LHC data.

Contribution

It presents a novel framework emphasizing the role of a dynamically generated jet resolution scale and coherent parton branching in jet quenching phenomena.

Findings

Most jets at LHC are unresolved, losing energy as a single coherent emitter.

The jet core remains largely unmodified, explaining intra-jet structure preservation.

The model aligns with current experimental observations of jet suppression.

Abstract

We propose a new description of the jet quenching phenomenon observed in nuclear collisions at high energies in which coherent parton branching plays a central role. This picture is based on the appearance of a dynamically generated scale, the jet resolution scale, which controls the transverse resolution power of the medium to simultaneously propagating color probes. Since from the point of view of the medium all partonic jet fragments within this transverse distance act coherently as a single emitter, this scale allows us to rearrange the jet shower into effective emitters. We observe that in the kinematic regime of the LHC, the corresponding characteristic angle is comparable to the typical opening angle of high energy jets such that most of the jet energy is contained within a non-resolvable color coherent inner core. Thus, a sizable fraction of the jets are unresolved, losing energy as a single parton without modifications of their intra-jet structure. This new picture provides a consistent understanding of the present data on reconstructed jet observables and constitute the basis for future developments.