Workshop: Jet Physics: From RHIC/LHC to EIC

Room C-120 (Physics Building)

Room C-120

Physics Building

Room C-120 (called “Peter Paul Seminar Room”) on the C-floor of the Physics Building. Once registered for the workshop, the online participants will receive a zoom link to connect to the workshop.

This event is part of the CFNS workshop/ad-hoc meeting series. See the CFNS conferences page for other events.

Location: Room C-120 (called “Peter Paul Seminar Room”) on the C-floor of the Physics Building. Once registered, the online participants will receive a zoom link via email.

Jet studies have played a key role in the exploration of QCD since its conception. With the advances in experimental techniques and theory developments over time, jets have become powerful tools for QCD physics, such as exploring the fundamental properties and regimes of QCD and probing the cold and hot nuclear medium in eA, pA, and AA collisions. In recent years, measurements of jets and jet substructure at RHIC and LHC have progressed significantly. In the meantime, theoretical developments in computing jet cross-sections and their substructures within perturbative QCD and effective field theory as well as introducing various grooming techniques have further triggered renewed interest and novel measurements in the field. Concurrently, Monte Carlo simulations in understanding jets inside both cold and dense medium such as large nuclei and quark-gluon plasma have seen significant progress in the last few years, e.g. within the JETSCAPE framework. On top of that, the sPHENIX experiment at RHIC and the STAR forward upgrade will start data taking in early 2023 and 2022, respectively,  and will undoubtedly provide exciting results on jet observables. With all these advancements, this is the opportune time to have a focused discussion on jet physics, to take advantage of the knowledge accumulated for jet studies at RHIC and LHC, and used for jet studies at the EIC. The usefulness of jets for EIC physics is highlighted in the EIC yellow report.

This workshop will bring together senior researchers, postdoctoral fellows, and talented graduate students to discuss the exciting recent developments and future direction in jet physics in both proton and heavy nucleus collisions, especially novel opportunities for jet physics at the EIC. The goal of our workshop is to summarize the accomplishments and provide guidance on jet physics, to inform the community on the synergy and difference in jet physics between RHIC/LHC (pp, pA, AA) and EIC (ep, eA). 

Organizing committee:

  • Aditya Prasad Dash
  • Alba Soto Ontoso
  • Andrew Larkoski
  • Anne Sickles
  • Anthony Hodges
  • Ayanabha Das
  • Babak Kasmaei
  • Babu Pokhrel
  • Benjamin Nachman
  • Brian Page
  • Charles Joseph NAIM
  • Chengtai Tan
  • Chinmoy Dey
  • Daniel Reichelt
  • Dennis Perepelitsa
  • Duff Neill
  • Farid Salazar
  • Felix Ringer
  • Frank Petriello
  • George Sterman
  • Goutam Das
  • Hao-yu Liu
  • Harleen Dahiya
  • Huan Huang
  • Ian Moult
  • James Mulligan
  • Jasmine Brewer
  • Jaydeep Datta
  • Jia Jiangyong
  • Jin Huang
  • Jingjing Pan
  • John Lajoie
  • João Barata
  • Kajal Samanta
  • Kyle Lee
  • Liang Zheng
  • Love Preet
  • Marcelo Munhoz
  • MC Kumar
  • Megan Connors
  • Miguel Arratia
  • Ming Li
  • Nihar Sahoo
  • Niseem Abdelrahman
  • Paul Caucal
  • Philip Velie
  • Raghav Kunnawalkam Elayavalli
  • Rajeev Singh
  • Roli Esha
  • Rongrong Ma
  • Rosi Reed
  • Samuel Alipour-fard
  • Sasza Czajka
  • Sebastian Tapia
  • Simon Schneider
  • Somadutta Bhatta
  • Tejes Gaertner
  • Tristan Protzman
  • Varun vaidya
  • Vladimir Skokov
  • Wai Kin Lai
  • Weiyao Ke
  • Wenbin Zhao
  • William Horowitz
  • Wouter Waalewijn
  • Xiaohui Liu
  • xiaohui Liu
  • Xin-Nian Wang
  • Yacine Mehtar-Tani
  • Yang-Ting Chien
  • Yasuki Tachibana
  • Yen-Jie Lee
  • Zhongbo Kang
  • Zuhal Seyma Demiroglu
  • 硕 林
    • Opening: Breakfast + Welcome
      • 1
      • 2
        Speaker: Abhay Deshpande (Stony Brook University)
      • 3
        Workshop Logistics
        Speaker: Zhongbo Kang (UCLA)
    • Long: Wednesday Morning
      Convener: Zhongbo Kang (UCLA)
    • Break: Morning
    • Short: Wednesday Morning
      Convener: Xin-Nian Wang (Lawrence Berkeley National Laboratory)
      • 7
        (online) Flavor flow and factorization in jets
        Speaker: George Sterman (Stony Brook University)
      • 8
        Final-state interactions in electron-ion collisions in eHIJING

        Jet plays a central role in physics at future electron-ion colliders, bridging experimental observables and the partonic structure of the atomic nuclei at high energy. In large nuclei, enhanced final-state jet-nucleus interactions cause transverse momentum broadening of jets and modifications of jet fragmentation. Such modifications are also channels to probe small-$x$ gluon distribution in the nucleus. We developed the electron-Jet-Multiple-Interaction-Generator (eHIJING) to study the interplay of momentum broadening and medium-modified jet fragmentation and further analyzed theoretical uncertainty using different calculations of in-medium parton splittings. The model is applied to describe semi-inclusive deep inelastic scattering data from CLAS, HERMES, and EMC experiments. I will also discuss future developments towards the study at the electron-ion colliders.

        Speaker: Weiyao Ke (UCB & LBNL)
    • Lunch: Wednesday
    • Long: Wednesday Afternoon
      Convener: Zhongbo Kang (UCLA)
      • 9
        Phenomenology of jet angularities at NLO+NLL’ accuracy
        Speaker: Daniel Reichelt
      • 10
        (online) Precise prediction for track-based measurements

        The superior angular resolution with which charged particle tracks can be measured is important for jet substructure measurements. Theoretically, track-based measurements are sensitive to hadronization, which is described by track functions. I will discuss some recent progress in extending the track function formalism to order alpha_s^2 (2108.01674, 2201.05166 and ongoing work), bringing precise predictions for track-based observables within reach.

        Speaker: Wouter Waalewijn (University of Amsterdam)
      • 11
        (online) Jet tomography in DIS now (HERA) and in the future (EIC)
        Speaker: Miguel Arratia (University of California, Riverside)
    • Break: Wednesday Afternoon
    • Short: Wednesday Afternoon
      Convener: Brian Page (Brookhaven National Laboratory)
      • 12
        Unveiling Nucleon 3D Chiral-Odd Structure with Jet Axes

        We reinterpret jet clustering as an axis-finding procedure which, along with the proton beam, defines the virtual-photon transverse momentum $q_T$ in deep inelastic scattering (DIS). In this way, we are able to probe the nucleon intrinsic structure using jet axes in a fully inclusive manner, similar to the Drell-Yan process. We present the complete list of azimuthal asymmetries and the associated factorization formulae at leading power for deep-inelastic scattering of a nucleon. The factorization formulae involve both the conventional time-reversal-even (T-even) jet function and the T-odd one, which have access to all transverse-momentum-dependent parton distribution functions (TMD PDFs) at leading twist. Since the factorization holds as long as $q_T \ll Q$, where $Q$ is the photon virtuality, the jet-axis probe into the nucleon structure should be feasible for machines with relatively low energies such as the Electron-Ion Collider in China (EicC). We show that, within the winner-take-all (WTA) axis-finding scheme, the coupling between the T-odd jet function and the quark transversity or the Boer-Mulders function could induce sizable azimuthal asymmetries at the EicC, the EIC and HERA. We also give predictions for the azimuthal asymmetry of back-to-back dijet production in $e^+e^-$ annihilation at Belle and other energies.

        Speaker: Wai Kin Lai (South China Normal University)
      • 13
        (online) Neutral-Current Electroweak Physics and SMEFT Studies at the EIC

        We study the potential for precision electroweak measurements and beyond-the-Standard Model searches using cross-section asymmetries in neutral-current deep inelastic scattering at the EIC.

        Speaker: Frank Petriello (Northwestern University)
    • Opening: Breakfast
    • Long: Thursday Morning
      Convener: Xin-Nian Wang (Lawrence Berkeley National Laboratory)
      • 14
        Jet substructure from archived e+e- data at 91.2 GeV from ALEPH
        Speaker: Yen-Jie Lee (Massachusetts Institute of Technology)
      • 15
        Lund multiplicity for precision physics
        Speaker: Alba Soto Ontoso (IPhT)
      • 16
        (online) Why we need factorization for jet physics in Heavy Ion collisions.

        I argue that the jet transport parameter used in literature as a measure of jet quenching should be further factorized to manifestly separate out the universal physics of the Quark Gluon Plasma medium from the properties of the jet. Doing so will allow us to considerably expand the study of jets in Heavy Ion collisions to a precision computation of a vast array of distinct jet substructure observables currently available for pp and ep colliders. Factorization makes this possible by allowing us to recompute the jet function for different observables while reusing the definition of the medium structure function which can be proved to be universal irrespective of the medium size. Furthermore, factorization provides us with an operator definition for the universal medium physics which is especially important for a strongly coupled medium for efficient computation on the lattice/Quantum computer. Factorization will also help establish universality of functions between jet observables in heavy ion collisions and the upcoming Electron Ion collider.

        Speaker: Varun vaidya (MIT)
    • Break: Coffee Break
    • Short: Thursday Morning
      Convener: Brian Page (Brookhaven National Laboratory)
      • 17
        Precision boson-jet azimuthal decorrelation at hadron colliders

        The azimuthal angular decorrelation of a vector boson and jet is sensitive to QCD radiation, and can be used to probe the quark-gluon plasma in heavy-ion collisions. By using a recoil-free jet definition, the sensitivity to contamination from soft radiation on the measurement is reduced, and the complication of non-global logarithms is eliminated from our theoretical calculation. Such jet definitions also significantly simplify the calculation for a track-based measurement, which is preferred due to its superior angular resolution. I will discuss the factorization in Soft-Collinear Effective Theory and show that potential glauber contributions do not spoil our factorization formalism, at least up to and including order $α_s^3$. The resummation is carried out using the renormalization group, and all necessary ingredients are collected or calculated. I will also discuss phenomenological studies, finding an enhanced matching correction for high jet pT due to the electroweak collinear enhancement of a boson emission off di-jets. By comparing with the Pythia event generator, I will show that our observable is very robust to hadronization and the underlying event.

        Speaker: Dr Yang-Ting Chien (Georgia State University)
      • 18
        Direct Photon-Jet Measurements at RHIC

        Measurements of jets and jet fragments correlated to a high-momentum direct photon have been a vital tool for studying a variety of quantum chromodyamical processes seen at the Relativistic Heavy Ion Collider (RHIC). Most notably, direct photons serve as a colorless, well-calibrated probe for studying the jet modification seen in ultrarelativistic nucleus-nucleus collisions caused by the interaction of hard-scattered partons with the QGP medium. The colorless nature of direct photons further makes them an excellent way to study jet-producing hard-scatterings in any collision system, as they can carry information directly from the hard scattering without any final-state fragmentation effects. In this talk I will discuss direct photon-jet measurements from the PHENIX and STAR experiments at RHIC across $p+p$, $d+Au$, and $Au+Au$ collision systems and their impact on our understanding of QCD, jets, and the QGP. I will conclude by discussing future prospects for such measurements with the new, state-of-the-art jet detector, sPHENIX, scheduled to begin taking data in 2023.

        Speaker: Anthony Hodges (University of Illinois)
    • Lunch
    • Long: Thursday Afternoon
      Convener: Brian Page (Brookhaven National Laboratory)
      • 19
        Exploring the transition from perturbative to non-perturbative QCD at the LHC
        Speaker: James Mulligan (UC Berkeley)
      • 20
        (online) Leading jet cross sections and comparison to experimental data
        Speaker: Felix Ringer (YITP Stony Brook)
      • 21
        (online) Data-driven extraction of quark and gluon jet substructure
        Speaker: Jasmine Brewer (CERN)
    • Break: Coffee Break
    • Short: Thursday Afternoon
      Convener: Yacine Mehtar-Tani (Brookhaven National Laboratory)
      • 22
        Resurrecting Parton-Hadron Duality Systematically
        Speaker: Duff Neill (LANL)
      • 23
        Back-to-back inclusive dijets in DIS at small x: NLO results
        Speaker: Paul Caucal (Brookhaven National Laboratory)
    • Opening: Breakfast
    • Long: Friday Morning
      Convener: Xin-Nian Wang (Lawrence Berkeley National Laboratory)
      • 24
        Jets and their substructure: A journey from LHC to RHIC to EIC
        Speaker: Dr Raghav Kunnawalkam Elayavalli (Yale University and BNL)
      • 25
        Safely Eating Junk: Pileup and Infrared Radiation Annihilation (PIRANHA)
        Speaker: Alipour-fard Alipour-fard (MIT)
      • 26
        (online) Jet Physics in sPHENIX: Learning from the LHC and Preparing for the EIC
        Speaker: Dennis Perepelitsa (University of Colorado Boulder)
    • Break
    • Short: Friday Morning
      Convener: Yacine Mehtar-Tani (Brookhaven National Laboratory)
      • 27
        (online) The role of vacuum-like and medium-induced emissions in jet quenching
        Speaker: Konrad Tywoniuk (University of Bergen)
      • 28
        (online) Jet fragmentation & substructure in nuclear collisions
        Speaker: Anne Sickles (University of Illinois)
    • Lunch
    • Long: Friday Afternoon
      Convener: Yacine Mehtar-Tani (Brookhaven National Laboratory)
      • 29
        Jet quenching in anisotropic plasmas
        Speaker: João Barata (BNL/IGFAE)
      • 30
        (online) Single Inclusive Jet Production in pA Collisions at NLO

        My talk is baesed on our work of presenting the first complete next-to-leading- order (NLO) prediction for the single inclusive jet production in pA collisions at forward rapidities within the color glass condensate (CGC) effective theory. Our prediction is fully differential over the final state physical kinematics, which allows the implementation of the full jet clustering algorithm in our calculation, as well as any other infra-red safe observables. The NLO calculation is setup with the aid of the observable originated power counting framework we proposed which gives rise to the novel soft contributions in the CGC factorization. We achieve the fully-differential calculation by constructing suitable subtraction terms to handle the singularities in the real corrections. The subtraction contributions can be exactly integrated analytically. The NLO calculation demonstrates explicitly the validity of the CGC factorization theorem to the jet production. Furthermore, as a byproduct of the subtraction method, we also derive the fully analytic cross section for the forward jet production in the small-R limit. We show that in the small-R limit, the forward jet cross section can be factorized to a semi-hard cross section that produces a parton and the semi-inclusive jet function (siJF),just like the jet production in the central region where exactly the same siJF shows up. We argue this feature holds for generic jet productions in the CGC framework. Last, we show numerical predictions of the jet transverse momentum and energy distributions. Like the forward hadron production, the obtained NLO result also exhibits the negative cross section in the large jet transverse regime, this talk also contains our solution to this which is the threshold resummation.

        Speaker: Hao-yu Liu (Beijing Normal University)
      • 31
        (online) Probing Gluon Bose Correlation Through Trijet Production in Deep Inelastic Scattering

        In recent years, there has been rising interest in trijet production in Deep Inelastic Scattering (DIS) within the small-x regime as a potential channel for probing gluon saturation. Motivated by the near side ridge structure of two particle long range rapidity correlation observed both at RHIC and LHC, we demonstrate that similar near side azimuthal angular correlation exists in the trijet production in DIS using the McLerran-Venugopalan model. We specifically focus on diffractive quark-antiquark dijet plus a gluon jet production. The origin of the near side azimuthal angular enhancement is traced back to the two gluon Bose correlation in the nuclear wavefunction. The trijet production in DIS offers a great opportunity to understand two particle correlations in nuclear wavefunction at the future Electron-Ion Collider.

        Speaker: Ming Li (North Carolina State University)
    • Break: Coffee Break
    • Short: Friday Afternoon
      Convener: Zhongbo Kang (UCLA)
      • 32
        (online) Prospects for measurement of the dijet transverse momentum decorrelation spectrum at Belle II

        Jets are expected to play an important role in nucleon structure measurements at current and near-future collision experiments. In order to effectively use jets for such analyses, their properties need to be understood across a wide range of energies. While high energy hadron collision experiments have been studying jet physics for many years, the extension to much lower energies remains relatively unexplored. Belle II is a next generation B-factory, observing electron-positron collisions at a center of mass energy around 10.6 GeV. We perform measurements of jet observables at the Belle II experiment to provide measurements of jet observables at these energies. The clean environment of Belle II is expected to allow us to constrain nonperturbative aspects of jets. In particular, we present the current status of ongoing measurement of the transverse momentum decorrelation spectrum in dijet events, which can be compared to recently published theoretical results in order to establish the validity of such calculations at lower energies.

        Speaker: Simon Schneider (Duke University)
      • 33
        (online) Are Jets Narrowed or Broadened in e+A SIDIS?
        Speaker: William Horowitz (University of Cape Town)
      • 34
        Speakers: Brian Page (Brookhaven National Laboratory), Megan Connors (Georgia State University RBRC), Xin-Nian Wang (Lawrence Berkeley National Laboratory), Dr Yacine Mehtar-Tani (Brookhaven National Laboratory), Zhongbo Kang (UCLA)