The highly-successful program of jet quenching in heavy-ion collisions relies upon a separation of energy scales between the jet $p_T$ and the medium. At leading power in this high-$p_T$ ``eikonal'' expansion, scattering in the medium leads to isotropic transverse momentum broadening and radiative energy loss, but the medium is approximately static in this limit. When extended to incorporate...
As energetic patrons produced in heavy-ion collisions traverse the quark-gluon plasma, they lose energy before fragmenting into a jet of particles such that the observed jet is modified compared to jets produced in p+p collisions. In heavy-ion collisions, the number of jets observed is suppressed and the distribution of particles or energy within the jet is modified compared to expectations...
Jet quenching measurements in central ultra-relativistic heavy ions collisions are a principle experimental probe of the quark-gluon plasma (QGP). The measurement resolution is limited, particularly at lower values of transverse momentum, by the high density of background particles. Many recent studies have demonstrated that neural networks (NNs) trained on jet substructure are capable of...
Energy-energy correlators(EECs) has recently emerged as an excellent jet substructure to study space-time information of parton shower. We explore the EECs within $\gamma$-jets using our LBT and CoLBT-hydro frameworks. We investigate the effects of jet quenching, medium-induced gluon radiation, and medium response on EECs in AA collisions compared to pp collisions. Additionally, we find that...
Jet substructure provides precise tests of Quantum Chromodynamics (QCD) and offers a distinct way to study hadronization mechanisms, compared to measurements of hadrons alone. QCD predicts that jet radiation patterns depend on the mass and color charge of the initiating parton. Parton showers, in particular, are sensitive to the Casimir factors of quarks and gluons, as well as the parton mass,...
Energy-energy correlators and their three point counterpart have recently been of great interest to the heavy ion jet community as they directly provide the virtuality scale and are relatively simple to calculate. Recent measurements of the two point correlator in PbPb collisions compared to pp collisions by CMS show interesting trends, even when accounting for the energy loss causing a shift...
Quark gluon plasma (QGP), when viewed at length scales of order the inverse of its temperature, behaves as a strongly coupled liquid. However, when it is probed at shorter length scales or with sufficiently high momentum transfer, asymptotic freedom mandates the presence of quark-like and gluon-like quasi-particles. High energy partons within jets can trigger these high-momentum exchanges,...
Relativistic fluid dynamics remains the backbone of modern simulations, which affects both bulk properties and rare probes such as jets. However, there have long been questions about whether it is being used outside its regime of validity in modern simulations. An important new tool for answering this question is a causality analysis -- if the evolution equations do not respect relativistic...
We introduce a sub-eikonal anisotropic contribution to jet-broadening, "jet drift," that couples to the flow of the nuclear medium, showing that this effect results in a deflection of hard partons, and thus jets, in the direction of the medium flow. We study Two-jet observables i.e. $v_{2}$ and acoplanarity for $\sqrt{s} = $ 5.02 TeV PbPb collisions at the LHC. We show that jet drift leads to...
The new sPHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has recently finished in its inaugural physics run with proton-proton and gold-gold collisions in 2024. sPHENIX is a large acceptance and high rate experiment, equipped with hermetic electromagnetic and hadronic calorimeter systems, the latter of which is unique at RHIC. The calorimeters, along with an efficient trigger...
The Large Hadron Collider beauty (LHCb) experiment allows for the exploration of jet substructure in novel ways. It is a fully instrumented spectrometer in the forward region, permitting increased sensitivity for heavy flavor hadron production as well as jets initiated by a light quark produced in association with a Z0 boson. This allows for an analysis of the mass and flavor dependence of jet...
Observables based on multiplicity play a crucial role in jet measurements. An influential contribution to the analysis of event multiplicity distributions is the Koba-Nielsen-Olesen (KNO) scaling hypothesis, which states that the multiplicity distributions can all be collapsed onto a universal scaling curve. Phenomenological studies based on proton–proton collisions have found a similar...
Substructure measurements of jets containing heavy-flavor hadrons play an important role in testing pQCD calculations in proton-proton (pp) collisions and are critical tools for studying the quark-gluon plasma (QGP) created in heavy-ion collisions. We study three different D0-tagged jet axis definitions with varying degrees of sensitivity to wide-angle radiation: Standard, Soft Drop groomed...
Measurements of jet substructure observables in heavy-ion collisions can constrain how energetic partons interact with the medium. Though there has been remarkable progress in particle-species-inclusive jet substructure measurements, a complete understanding of the identified particle composition of the jet and its modification in heavy-ion collisions remains elusive. Jet quenching models...
We explore modification of jet properties in high-multiplicity proton-proton (pp) collisions at $\sqrt{s} = 13$ TeV, utilizing the PYTHIA 8 Monash 2013 Monte Carlo simulation. While the formation of a quark-gluon plasma (QGP) is typically associated with jet quenching, our investigation focuses on jet modifications arising purely from non-QGP mechanisms, including color reconnection (CR) and...
Collinear drop observables suppress energetic, collinear contributions and enhance the sensitivities to soft radiation where medium modifications are most significant. While the Lund plane contains comprehensive information about radiation, collinear drop observables can be concretely designed to probe specific regions of phase space which qualitative features of medium modifications may...
