BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:C3NT Program: Connecting Theory to Collider Data in the Era of Pre cision Saturation Physics DTSTART:20270308T010000Z DTEND:20270319T110000Z DTSTAMP:20260704T065200Z UID:indico-event-18423@indico.global CONTACT:wenbinzhao@ccnu.edu.cn\;xiangyushui@ccnu.edu.cn\;c3nt@ccnu.edu.cn DESCRIPTION:Speakers: Wenbin Zhao (Wayne State University)\, Heikki Mänty saari (University of Jyväskylä)\, Farid Salazar (Institute for Nuclear T heory\, University of Washington)\, Paul CAUCAL (Subatech\, Nantes Univers ité/CNRS-IN2P3)\, Bowen Xiao (The Chinese University of Hong Kong\, Shenz hen (CN))\, Vladimir Skokov\, Charlotte Van Hulse (Universidade de Santiag o de Compostela (ES))\n\nThe physics of gluon saturation at small Bjorken- $x$ has emerged as one of the most compelling frontiers in quantum chromod ynamics (QCD). As parton densities grow with decreasing momentum fraction $x$\, gluon occupation numbers become large enough that non-linear recombi nation effects\, encoded in the Color Glass Condensate (CGC) effective fie ld theory\, are expected to tame this growth and give rise to a universal saturation scale $Q_s(x)$. Despite decades of theoretical development and tantalizing hints from HERA\, RHIC\, and the LHC\, definitive evidence for gluon saturation remains elusive. The forthcoming Electron-Ion Collider ( EIC)\, together with ongoing programs at the LHC and RHIC\, will offer unp recedented opportunities to probe the saturated regime with high precision .\nThis program is sponsored by the Central China Center for Nuclear Theor y (C3NT)\, held at the Institute of Particle Physics (IOPP) at CCNU. It ai ms to bring together experts in small-$x$ theory\, perturbative QCD\, phen omenology\, event-generator development\, and experimental physics to asse ss the current status and chart the path forward for establishing gluon sa turation as a quantitative science. The main goals are:\n\n\nMap experimen tal observables sensitive to gluon saturation. A wide array of measurement s—inclusive and diffractive deep-inelastic scattering (DIS) structure fu nctions\, exclusive vector meson and DVCS cross sections\, forward particl e production and correlations in p+A and e+A collisions\, di-hadron and ph oton-hadron azimuthal correlations\, and multiplicity fluctuations—carry distinct signatures of non-linear QCD evolution. By systematically catalo ging and comparing these observables across collider systems and kinematic regimes\, we aim to identify the most discriminating channels and develop a coherent experimental strategy for the EIC era and beyond. Special atte ntion will be given to observables in ultra-peripheral collisions (UPCs) a t the LHC\, which already provide photon-nucleus scattering data at unprec edented energies.\n\n\nAdvance the theoretical framework to next-to-leadin g order and beyond. The CGC/saturation framework has matured considerably in recent years with the completion of key next-to-leading order (NLO) cal culations\, including the NLO Balitsky-Kovchegov (BK) and JIMWLK evolution equations\, NLO impact factors for inclusive and exclusive DIS\, and NLO corrections to single and double inclusive particle production. However\, significant challenges persist. The NLO BK equation suffers from instabili ties and requires careful resummation of large logarithms—through kinema tic constraint prescriptions\, collinear resummations\, or the treatment o f running coupling effects—to yield stable and physically meaningful evo lution. The workshop will critically assess the current status of these NL O calculations\, identify remaining gaps (such as full NLO exclusive diffr action and NLO corrections to multi-particle correlations)\, and discuss s trategies for pushing the framework toward NNLO accuracy where needed.\n\n \nQuantify and reduce theoretical uncertainties. Robust discovery of satur ation effects demands rigorous uncertainty quantification\, a dimension th at has historically been underdeveloped in CGC phenomenology. Sources of t heoretical uncertainty include the sensitivity to initial conditions for s mall-x evolution (such as the initial saturation scale\, its impact-parame ter dependence\, and the proton/nuclear geometry)\, the scheme dependence of NLO calculations\, the treatment of the transition between dilute (DGLA P/BFKL) and dense (BK/JIMWLK) regimes\, higher-order corrections beyond NL O\, subeikonal corrections\, and the modeling of confinement effects at la rge dipole sizes. We will discuss the development of systematic Bayesian i nference frameworks for CGC fits to data\, analogous to those employed in global collinear PDF analyses\, that can propagate these uncertainties to predictions for future measurements. Establishing clear benchmarks for whe n saturation-based and linear-evolution-based descriptions diverge—and w ith what statistical significance—will be a central theme.\n\n\nDevelop and benchmark event generators incorporating saturation physics. Translati ng theoretical predictions from the CGC framework into fully differential\ , hadron-level simulations is essential for direct comparison with experim ental data and for designing future measurements. Current Monte Carlo tool s—such as IP-Sat-based generators and modules within Pythia or SHERPA— implement saturation effects at varying levels of sophistication. The work shop will address key open questions in event-generator development\, incl uding the consistent matching of CGC-based initial-state calculations with final-state parton showers and hadronization models\, the implementation of NLO CGC cross sections in a Monte Carlo framework while preserving posi tive-definite event weights\, the modeling of nuclear geometry and event-b y-event fluctuations in e+A and p+A collisions\, and the interface with de tector simulations for the EIC and LHC experiments. We aim to foster coord ination among generator developers and identify a common set of validation benchmarks.\n\n\nAdvance phenomenological studies connecting theory to da ta. A rich body of phenomenological work connects CGC predictions to exist ing data from HERA\, RHIC\, and the LHC\, and generates projections for th e EIC. Key topics include global analyses of DIS and diffractive data with in dipole models at NLO accuracy\, the interpretation of forward rapidity measurements in p+p and p+A collisions at the LHC (including forward J/ψ\ , D-meson\, and direct photon production) as probes of low-x gluon densiti es\, the extraction of the saturation scale and its nuclear enhancement fr om coherent and incoherent diffractive vector meson production\, the study of multi-particle correlations\, and projections for EIC measurements inc luding their expected impact on constraining saturation models. The worksh op will emphasize the importance of performing apples-to-apples comparison s between competing theoretical frameworks—CGC\, kT​-factorization\, c ollinear factorization with nuclear PDFs\, and hybrid approaches—applied to the same observables and kinematic regions.\n\n\nBy fostering interdis ciplinary dialogue through invited talks\, working-group discussions\, and dedicated benchmarking sessions\, our Small-x and Gluon Saturation worksh op will consolidate the community's efforts toward establishing saturation physics on a firm quantitative foundation. We anticipate that the converg ence of theorists\, phenomenologists\, event-generator developers\, and ex perimentalists will catalyze new collaborative initiatives—particularly in the context of EIC physics preparation—and produce a coherent roadmap for the discovery and characterization of non-linear QCD dynamics in the coming decade.\n \nProgram format:\nThe workshop will run for two weeks w ith no parallel sessions. Each day will feature an average of four long ta lks and ample time for discussions.\n\n\nhttps://indico.global/event/18423 / LOCATION:Institute of Particle Physics\, 409 (Central China Normal Univers ity) URL:https://indico.global/event/18423/ END:VEVENT END:VCALENDAR