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2025 SURGE Collaboration Meeting and Workshop

23–25 Jun 2025
Physics and Astronomy Building
US/Pacific timezone

Contribution List

38 out of 38 displayed
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  1. 7. Welcome
    Zhongbo Kang (UCLA)
    23/06/2025, 08:50
  2. 8. SURGE: Status Overview and Progress
    Bjoern Schenke (Brookhaven National Lab)
    23/06/2025, 09:00
  3. 9. Overview of Initial Stage working group
    Andrey Tarasov (North Carolina State University)
    23/06/2025, 09:25
  4. 10. Overview of Small x + NLO working group
    Zhongbo Kang (UCLA)
    23/06/2025, 09:50
  5. 12. Overview of Final Stage working group
    Prof. Jacquelyn Noronha-Hostler (University of Illinois Urbana Champaign)
    23/06/2025, 10:45
  6. 11. Overview of Spin working group
    Matthew Sievert (New Mexico State University)
    23/06/2025, 11:10
  7. 13. Overview of Global Analysis working group
    Prof. Fred Olness (Southern Methodist University (US))
    23/06/2025, 11:35
  8. 33. Recent jet-based measurements sensitive to TMDs in ep collisions
    Miguel Arratia, Miguel Arratia Munoz
    23/06/2025, 14:00
  9. 34. Experimental probes of gluon saturation in UPCs
    Benjamin Jacob Gilbert (Lawrence Livermore Nat. Laboratory (US))
    23/06/2025, 14:25
  10. 31. Recent experimental progress in searching for gluon saturation
    Xiaoxuan Chu (BNL)
    23/06/2025, 14:50

    Understanding gluon saturation at small $x$ is a central question in high-energy nuclear physics, with deep implications for the non-linear regime of QCD. This talk presents an overview of recent experimental efforts aimed at uncovering signatures of gluon saturation, with a focus on two-particle azimuthal correlations in p+p, p+A, and d+A collisions. Despite theoretical predictions from the...

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  11. 6. A Neural-Network Extraction of Unpolarized Transverse-Momentum Distributions from Drell-Yan data
    Chiara Bissolotti (Argonne National Laboratory)
    23/06/2025, 15:45

    We present the first proof of concept extraction using neural networks (NNs) of the unpolarised transverse-momentum distributions (TMDs) at next-to-next-to-next-to- leading logarithmic (N3LL) accuracy. By offering a more flexible and adaptable approach, NNs overcome some of the limitations of traditional functional forms, providing a better description of data. This work focuses exclusively on...

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  12. 35. Gluon GPDs at small-x and global analysis
    Yuxun Guo
    23/06/2025, 16:10
  13. 36. Event Generator at the EIC
    Jordi Salinas San Martin, Jordi Salinas San Martín (University of Illinois at Urbana Champaign)
    23/06/2025, 16:35
  14. 29. nCTEQ25: Overview and Preliminary Results
    Peter Risse (Southern Methodist University)
    23/06/2025, 17:00

    We discuss the preliminary results of the new global nCTEQ25 nuclear PDF analysis, combining a number of our previous analyses into one consistent framework with updates to the underlying theoretical treatment as well as the addition of new available data. In particular, the nCTEQ24 global release will be the first nCTEQ release containing neutrino DIS scattering data in a consistent manner...

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  15. 37. Regge Factorization for ep Diffraction from EFT
    Prof. Iain Stewart
    24/06/2025, 09:00
  16. 25. Towards 3-loop Balitsky--Kovchegov: the non-conformal part
    Mathieu Giroux (McGill University)
    24/06/2025, 09:25

    The Balitsky–Kovchegov (BK) equation offers a tractable description of the high‑energy growth of gauge‑theory scattering amplitudes and the nonlinear saturation effects that eventually tame this growth. Motivated by the upcoming precision era at the Electron–Ion Collider (EIC)—whose extended kinematic reach promises decisive tests of saturation—we present a framework based on the...

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  17. 32. Calculation of sub-eikonal corrections for the dijet production in the background field method
    Andrey Tarasov (North Carolina State University)
    24/06/2025, 09:50

    The search of the signatures of saturation is one of the main goals of the future Electron-Ion Collider (EIC). In this regime the background field of the target is characterized by the shock-wave structure defined by the eikonal interactions. However, we expect that this limit will be hard to achieve at EIC, due to the moderate values of the scattering energies. Instead, the leading eikonal...

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  18. 23. Gluonic Gravitational Form Factors and Near-Threshold $J/\psi$ Photoproduction in Holographic QCD
    Kiminad Mamo
    24/06/2025, 10:45

    Abstract:

    Gravitational form factors (GFFs) of the nucleon furnish a three–dimensional
    map of the energy, momentum, pressure, and shear carried by QCD constituents,
    with gluonic contributions playing a decisive role. Complementing lattice QCD
    results, we employ a confining bottom‐up AdS/QCD model in which the bulk
    dilaton background simultaneously generates linear Regge trajectories...

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  19. 1. Probing orbital angular momentum distributions with elastic dijet production in ep collisions
    Brandon Manley (The Ohio State University)
    24/06/2025, 11:10

    We calculate the elastic production of dijets from electron collisions with a longitudinally polarized proton target at small values of the Bjorken $x$ variable. Building on the pioneering proposals of Hatta et al and Bhattacharya et al for measuring the quark and gluon orbital angular momentum (OAM) distributions, our focus is on both the longitudinal double spin asymmetry (DSA) and...

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  20. 30. Revisiting the Dihadron Angular Correlations in Forward pA collisions
    Wenbin Zhao (LBNL)
    24/06/2025, 11:35

    Dihadron angular correlations in forward pA collisions provide a sensitive probe of gluon saturation effects. In these processes, both gluon saturation and parton shower dynamics contribute to the observed de-correlation between back-to-back dihadron pairs. In our study, we employ the Color Glass Condensate (CGC) framework to perform a detailed numerical investigation of dihadron correlations...

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  21. 38. Modification of EEC in cold and hot nuclear medium
    Dr Xin-Nian Wang (Lawrence Berkeley National Lab. (US))
    24/06/2025, 13:30
  22. 5. Energy-energy correlators inside jets in $pp$ and $pA$ collisions
    Jani Penttala (UCLA)
    24/06/2025, 13:55

    Energy-energy correlators (EEC) are event-shape observables that have gained renewed interest in the recent years, due to them being less sensitive to the non-perturbative hadronization of the final-state particles. In this talk, I will discuss the EEC in $pp$ and $pA$ collisions in the collinear limit where the studied particles are inside the same jet. This type of EEC allows us to probe jet...

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  23. 22. Jet Energy-Energy Correlators in Deep Inelastic Scatterings
    Yu Fu
    24/06/2025, 14:20

    The jet energy-energy correlator (EEC), which measures angular correlations of energy flow inside jets, provides a sensitive probe of jet substructure and its modification by the nuclear medium. We compute the EEC for jets produced in electron-proton and electron-nucleus deep inelastic scattering, focusing on medium-induced corrections arising from final-state interactions in cold nuclear...

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  24. 3. Probing the Sivers Asymmetry with Transverse Energy-Energy Correlators in the Small-x Regime
    DIEGO PADILLA MONROY (UCLA)
    24/06/2025, 14:45

    We investigate transverse energy-energy correlators (TEECs) for both polarized and unpolarized targets in the small-x regime at the Electron-Ion Collider (EIC). Focusing on the approximately back-to-back electroproduction of a hadron-electron pair, we apply transverse-momentum-dependent (TMD) factorization formulas that incorporate TMD evolution for both event-shape observables and expand them...

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  25. 27. Sea quark TMD distributions at small-x
    Marcos Guerrero Morales (Temple University)
    24/06/2025, 15:40

    The Color Glass Condensate (CGC) is an effective field theory that describes the behavior of hadrons and nuclei at high energies (corresponding to small values of Bjorken-x), where the rapid growth of gluon densities is expected to be moderated by saturation effects. In this talk I will show that within the CGC dilute-dense formalism, the cross section for dijet production involving a small-x...

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  26. 24. Small-x asympototics of GPDs
    Huachen Sun (The Ohio State University)
    24/06/2025, 16:05

    We study the small-$x$ asymptotics of unpolarized generalized parton distributions (GPDs). Unlike the previous works in the literature, we consider the case of non-zero skewness. We show that the unpolarized GPDs at small $x$ are related to the eikonal dipole amplitude $N$, whose small-$x$ evolution is given by the BK/JIMWLK evolution equations. We show that the effect of non-zero skewness...

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  27. 14. Breakout Session: Final State WG
    24/06/2025, 16:30
  28. 15. Breakout Session: Global Analysis WG
    24/06/2025, 16:30
  29. 16. Breakout Session: Initial State WG
    24/06/2025, 16:30
  30. 17. Breakout Session: Small x and NLO WG
    24/06/2025, 16:30
  31. 18. Breakout Session: Spin WG
    24/06/2025, 16:30
  32. 39. What do we talk about when we talk about saturation?
    Peter Martin Jacobs (Lawrence Berkeley National Lab. (US))
    25/06/2025, 09:00
  33. 26. SIDIS in the target fragmentation region at small x
    Farid Salazar (Institute for Nuclear Theory, University of Washington)
    25/06/2025, 09:25

    Single inclusive hadron production in Deep Inelastic Scattering serves as standard candle observable for probing the 3D partonic structure of proton or nuclear targets. In this talk, I will focus on particle production in the target fragmentation region. At moderate Bjorken-x, this kinematic regime is described by the framework of transverse momentum dependent (TMD) fracture functions. To...

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  34. 40. CSS evolution as renormalization of a non-local composite operator
    Jamal Jalilian-Marian
    25/06/2025, 09:50
  35. 21. Born-Oppenheimer Renormalization group for High Energy Scattering
    Dr Haowu Duan (University of Connecticut)
    25/06/2025, 10:45

    We develop an approach to QCD evolution based on the sequential Born-Oppenheimer approximations that include higher and higher frequency modes as the evolution parameter is increased. This Born-Oppenheimer renormalization group is a general approach which is valid for the high energy evolution as well as the evolution in transverse resolution scale $Q^2$. We found that the evolution equation...

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  36. 4. Small-$x$ Helicity Evolution: First Study on the Impact of Polarized $pp$ Scattering Data
    Nicholas Baldonado (New Mexico State University)
    25/06/2025, 11:10

    We perform a phenomenological study of helicity-dependent parton distribution functions (hPDFs) using the KPS-CTT small-$x$ helicity evolution equations. Specifically, this new work presents the first study of the influence of polarized proton-proton ($pp$) scattering data whilst simultaneously analyzing inclusive and semi-inclusive deep-inelastic scattering data, all at $x < 0.1$. Polarized...

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  37. 20. Weizs\"acker-Williams Gluon Helicity Distribution and Inclusive Dijet Production in Longitudinally Polarized Electron-Proton Collisions
    Ming Li (The Ohio State University)
    25/06/2025, 11:35

    It is well-known that the back-to-back (correlation) limit of inclusive quark--antiquark dijet production in unpolarized high energy electron--proton collisions can probe the Weizs\"{a}cker-Williams (WW) gluon transverse momentum-dependent distribution (TMD) at small $x$. In this paper, we consider a helicity-dependent version of the same process: we study the double-spin asymmetry for...

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  38. 19. Closing Remarks
    Zhongbo Kang (UCLA), Bjoern Schenke (Brookhaven National Lab)
    25/06/2025, 12:00