Emergence of thermal recoil jets in high-energy heavy-ion collisions

TL;DR

This paper introduces the concept of thermal recoil jets in high-energy heavy-ion collisions, explaining their distinct properties and potential to reveal new insights into quark-gluon plasma behavior.

Contribution

It proposes a novel production mechanism for thermal recoil jets, distinct from hard jets, with unique dependencies and substructures, advancing the understanding of jet-medium interactions.

Findings

Thermal recoil jets exhibit different $p_T$ and $R$ dependencies from hard jets.

They can explain enhanced yields of certain jet types at specific angles and momenta.

Predicted jet substructures can be tested in future experiments.

Abstract

In the established paradigm of jet quenching in relativistic heavy-ion collisions, jets from initial hard parton scatterings are suppressed due to their interaction with the quark-gluon plasma (QGP) as they traverse the hot medium, serving as crucial tomographic probes of QGP properties. The QGP is also capable of absorbing and reprocessing energy deposited by the hard jets into emergent jet-like objects, providing a novel production mechanism of thermal recoil jets. These emergent thermal recoil jets exhibit distinct transverse momentum ($p_\mathrm{T}$) and jet-size ($R$) dependencies different from the hard jets, and naturally explain the puzzling observation of the enhanced yields of hadron or photon triggered jets at large azimuthal angle and solely at small $p_\mathrm{T}$ and large $R$. These thermal recoil jets are predicted to have unique substructures, such as their jet shape that increases with the radius and the thermal-like distribution of their constituents, which can be verified in future experimental analyses.