Conveners
Jets: (1)
- Mateusz Ploskon (Lawrence Berkeley National Lab. (US))
Jets: (2)
- Xin-Nian Wang (Lawrence Berkeley National Lab. (US))
Jets: (3)
- John William Harris (Yale University (US))
Jets: (4)
- Olga Evdokimov (University of Illinois at Chicago (US))
Quark-gluon plasma, which is a strongly coupled liquid at its natural length scales, must at the same time feature weakly coupled quark and gluon quasiparticles that appear only in hard processes that can resolve its short-length structure. In particular, high-energy partons in a jet shower can scatter off, and kick, the quark and gluon quasiparticles within a droplet of QGP when these Moliere...
Jet energy loss and transverse momentum broadening are controlled by the jet transport coefficient $\hat{q}$ in the QGP medium. Specifically, jet energy loss correlates with jet propagation length, while transverse momentum asymmetry caused by the gradient of $\hat{q}$ depends on the initial transverse coordinates. We study both the longitudinal and transverse jet tomography in dijet events by...
In this talk we use the recently introduced energy correlator framework for jet substructure in heavy-ion collisions to show how the radiation pattern of heavy quarks is modified by the presence of the QGP. We present an analytical calculation of the medium-modified 2-point energy correlator of a heavy quark jet determining how the dead-cone is populated by medium-induced radiation. We...
The suppression of jets in heavy-ion collisions can provide detailed information about the hot, dense plasma formed in these collisions at the LHC. Jet quenching in heavy-ion collisions is expected to depend on the mass of the fragmenting parton. For light partons, energy loss via gluon bremsstrahlung is expected to dominate, while for heavy-quark-initiated jets, collisional energy loss may...
Extensive studies of dijet momentum balance, inclusive jet shapes, and photon-tagged jet fragmentation functions have revealed a significant contribution of low transverse momentum ($p_\mathrm{T}$) particles to the energy momentum balance of dijet and photon-jets. Effects such as medium-induced radiation and medium response could contribute to the enhancement of low-$p_\mathrm{T}$ particles....
Previous analyses have shown a narrowing effect in the inclusive jet substructure. While this narrowing effect could be a result of jet quenching, it could also be caused due to a selection bias by which very quenched and broader jets are filtered out from the considered jet transverse momentum window. Photon-tagged jets, which correspond to a quark-enriched sample, can significantly reduce...
While experimental studies on jet quenching have achieved a large sophistication, the theoretical description of this phenomenon still misses some important points. One of them is the interplay of vacuum-like emissions, usually formulated in momentum space, with the medium induced ones that demand an interface with a space-time picture of the medium and thus must be formulated in position...
The study of jet substructure in heavy-ion collisions provides multiple tools for incisive exploration of jet-medium interactions and the mechanisms underlying jet quenching. Some results, however, remain disjoint: the jet mass and jet angularities, including girth and thrust, are strongly-correlated observables that have given seemingly conflicted answers on the angular quenching of jets...
This talk presents new measurements of inclusive jet yield suppression and correlation with event-plane orientation to elucidate the kinematic and path-length dependence of jet energy loss due to quenching. We report measurements of the inclusive charged-particle jet yield in central Pb--Pb collisions, with the large uncorrelated background mitigated using a novel event mixing technique. This...
sPHENIX is a new collider detector at RHIC designed for pioneering studies of the Quark-Gluon Plasma with high-p$_T$ jet and heavy flavor probes. The jet physics program particularly relies on the sPHENIX calorimeter system, which consists of large-acceptance, hermetic electromagnetic and hadronic sections designed for high-resolution measurements of photons, electrons, hadrons, and jets....
Prompt photons are created in the early stages of heavy ion collisions and traverse the QGP medium without any interaction. Therefore, photon-triggered jets can be used to study the jet quenching in the QGP medium. In this work, photon-triggered jets are studied through different jet and jet substructure observables for different collision systems and energies using the JETSCAPE framework....
Measuring the jet substructure in heavy-ion collisions provides exciting new opportunities to study detailed aspects of the dynamics of jet quenching in the hot and dense QCD medium created in these collisions. In this talk, we present new comprehensive ATLAS measurements of jet suppression and substructure performed using various jet radii and grooming techniques. New measurements of...
Partons traversing the hot and dense medium of deconfined color charges produced in collisions of heavy nuclei are expected to lose their energy primarily through medium-induced gluon bremsstrahlung. As a result, the amount of induced energy loss is expected to depend on the QCD color charge carried by the parton, i.e. depend on whether it is a quark- or a gluon-initiated jet. In this talk,...
Since the discovery of the jet quenching at RHIC, the in-medium interaction of hard scattered partons with the nuclear medium created by high-energy heavy-ion collisions has been an excellent tool to understand not only the transport properties of the medium but also its time evolution towards hadronization. The multi-differential measurement of the high momentum two-particle correlations can...
We present a unique signal of jet-induced medium excitations: the enhancement of baryon-to-meson ratios around the quenched jets [1]. To illustrate this, we study jet-particle correlations and the distributions of jet-induced identified particles with respect to the jet direction in Pb+Pb collisions at the LHC via a multi-phase transport model. We find a strong enhancement of baryon-to-meson...
The measurement of jets recoiling from a trigger hadron (hadron+jet) provides unique probes of medium-induced modification of jet production. Jet deflection via multiple soft scatterings with the medium constituents may broaden the azimuthal correlation between the trigger hadron and the recoiling jet. In addition, the tail of this azimuthal correlation may be sensitive to single-hard Moli`ere...
We present a novel approach to jet substructure in heavy-ion collisions formulated in terms of correlation functions of flux operators (energy correlators). This approach is based on the insight that the time scales in the jetโs evolution are imprinted into the angular scales of the correlator spectra. We study the two-point correlator of an in-medium massless quark jet, showing its...
We study the equilibration of a high-momentum parton traveling through a Quark-Gluon Plasma using QCD kinetic theory. We show that the energy and particle number are first transported to the soft sector by collinear cascade and then isotropized by elastic scatterings. For a static thermal background, we find that the jet wake can be described by a thermal distribution function with...
Even though the quark-gluon plasma produced in high-energy heavy ion collisions has been studied in detail for years, there are still properties that are not known to a good precision. One example of such property is the medium resolution length, which is related to the smallest angle of emission where the medium can still resolve the daughter particles as individual particles. This can be...
Jets provide a powerful tool to study the properties of hot nuclear matter and its effect on quantum processes. The degree of modification of jets by the medium depends on how well the medium can resolve the internal jet structure. In this work, we investigate the interplay between the multi-partonic structure of jets and their interaction with a strongly-interacting medium. Specifically, we...
Diffusion wake accompanying jet-induced Mach-cone is a unique feature of jet-medium interaction in high-energy heavy-ion collisions. We explore the 3D structure of the diffusion wake induced by triggered jets in Pb+Pb collisions at the LHC energy within the coupled linear Boltzmann transport and hydro model. We identify a valley structure caused by the diffusion wake on top of a ridge from the...
We propose a novel approach to investigate the evolution of jets in heavy-ion collisions by employing a combination of jet substructure measurements. Our method focuses on isolating the perturbative regime of jet evolution. As a proof of concept, we analyze the distribution of the hardest splitting above a transverse momentum scale, $k_{t,cut}$, in high-$p_t$ jets. For a $k_{t, cut}$ that is...
