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Correlations in Partonic and Hadronic Interactions (CPHI-2022)

Love Auditorium/LSRC B101 (Duke University)

Love Auditorium/LSRC B101

Duke University

Alessandro Bacchetta (University of Pavia and INFN Pavia) , Anselm Vossen (Duke University/JLab) , Bakur Parsamyan (Torino U.) , Harut Avagyan (Jefferson Lab) , Zhongbo Kang (UCLA) , Miguel Arratia (University of California, Riverside)

After previous iterations taking place in Yerevan (2009, 2018) and at CERN (2020), we are planning for a 4 day workshop which will take place in person at Duke University March 7-10.

The workshop will take place in Love Auditorium on Duke’s West campus. This workshop venue will provide ample space for social distancing and we strive to make the workshop as safe as possible by implementing measures like masking and distancing.

In particular the following COVID protocols will be implemented

  • Social distancing: All conference venues will be large enough to facilitate social distancing.
  • Masking Requirements: The workshop will require masking and the use of N95 masks is encouraged
  • No food or drink at the conference venue.

Please also consider the Duke guidelines for visitors relating to COVID.


Duke university is easily reached using RDU airport which is about 20 miles away and served by all major airlines. Several hotels of varying price range are located close to Duke Campus with several within walking distance and most providing shuttles to campus.

While a majority of the program will be by invitation, the organizers encourage the submission of abstracts for contributed talks. The abstracts can be submitted by following the link on the sidebar of this website. Limited funding to support travel is available. 

The organizers encourage in particular early career scientists to submit abstracts and participate in the workshop. The support of early career scientists and those from underrepresented groups will be a priority when considering funding requests.

The main goal of the workshop is to discuss important and recent results on the study of the 3D structure of protons, hadronization dynamics and initial-final state correlations from JLab12, CERN, BNL, DESY and KEK experiments as well as the resulting theory and phenomenology challenges for the extraction and interpretation of TMDs and GPDs from existing data. A further focus will be to identify relevant systematic uncertainties in the measurements and to inform possible future measurements. 


Registration and additional information on the workshop will be available on the workshop homepage


Below are key questions that we plan to address:


 Transverse Structure of nucleon and  QCD issues associated with 3D structure

  • Factorization issues in hadron production

  • Study of the QCD evolution properties of 3D PDFs.

  • Unintegrated and Generalized Transverse Momentum Distributions

  • Evolution of TMDs and fits to physical cross sections

  • MC generators for global analysis of 3D PDFs

  • Phenomenology of 3D parton distribution and fragmentation functions.

  • 3D PDFs from Lattice QCD.

  • Extraction of PDFs from di-hadron production.

  • Radiative corrections to hard scattering in exclusive and semi-inclusive processes


Partonic Structure beyond Densities

  • Nuclear modifications of distribution functions.

  • Target fragmentation and conditional probabilities

  • Higher twist asymmetries in SIDIS

  • New insights on 3D PDFs from non-perturbative models


Essential observables, which will direct the future experimental effort in

  • Leptoproduction with fixed target facilities at CERN, JLab and EIC

  • Drell-Yan lepton pair production and Drell-Yan plus jets

  • Higgs boson production and Higgs boson plus jets

  • Heavy flavor production

  • Soft particle production and multi-parton interactions


QCD in the Nuclear Environment}

  • PDF nuclear modifications and short-range nucleon correlations

  • Flavor dependence of nuclear modification effects

  • Nuclear partonic distributions including x>1 region 

  • Tagged SIDIS processes off nuclear targets

  • Hadronization processes in Nuclear SIDIS

  • Hard nuclear QCD processes and Color transparency


Please direct questions about the conference, travel or funding to the organizers.


Miguel Arratia, Harut Avakian, Alessandro Bacchetta, Zhongbo Kang, Bakur Pasamyan, Anselm Vossen (chair)


Local Organizing Committee:

Matthew McEneaney, Kathrine Parham, Connor Pecar, Simon Schneider, Anselm Vossen

This project is supported by the Initiatives Fund Program, a JSA commitment, to support programs, initiatives, and activities that further the scientific outreach, promote the science, education and technology of Jefferson Lab and benefit the Lab’s extended user community in ways that complement the Lab’s basic and applied research missions.

Registration for CPHI 2022
  • aaa aaa
  • Albi Kerbizi
  • Aleksandra Lelek
  • Alessandro Bacchetta
  • Alexander Kovner
  • Alexei Prokudin
  • Alexey Guskov
  • Alexey Vladimirov
  • Andrea Moretti
  • Andrea Signori
  • Anjie Gao
  • Anna Martin
  • Anselm Vossen
  • April Townsend
  • Aram Kotzinian
  • Aurore Courtoy
  • Bakur Parsamyan
  • Bishnu Karki
  • Bo Yu
  • Caroline Riedl
  • Catarina Quintans
  • Chiara Bissolotti
  • Christian Weiss
  • Christopher Dilks
  • Connor Pecar
  • Cédric Mezrag
  • Daniel Hackett
  • Daria Sokhan
  • Farid Salazar
  • Fatiha Benmokhtar
  • Feng Yuan
  • Francesco Giovanni Celiberto
  • Franco Bradamante
  • Francois-Xavier Girod-Gard
  • Fulvio Tessarotto
  • Gregory Matousek
  • Haowu Duan
  • Harut Avagyan
  • Holly Szumila-Vance
  • Iain Stewart
  • Ignazio Scimemi
  • Igor Akushevich
  • Jennifer Rittenhouse West
  • Johannes Michel
  • John Terry
  • Katherine Parham
  • Kyungseon JOO
  • Leonard Gamberg
  • Maria Zurek
  • Mariaelena Boglione
  • Martin Faessler
  • Matthew McEneaney
  • Mees van Kampen
  • Miguel Arratia
  • Ming Li
  • Miroslav Finger
  • Mriganka Mouli Mondal
  • Nobuo Sato
  • Oleg Denisov
  • Pasquale Di Nezza
  • Patrizia ROSSI
  • Peter Schweitzer
  • Pia Zurita
  • Rabah Abdul Khalek
  • Ralf Seidl
  • Reed Hodges
  • Riccardo Longo
  • Richard Capobianco
  • Romain Kiba Bassandi
  • Saraswati Pandey
  • Shohini Bhattacharya
  • Simon Schneider
  • Simonetta Liuti
  • Sookhyun Lee
  • Stan Srednyak
  • Timothy Hayward
  • Vladimir Skokov
  • Weiyao Ke
  • Xiaoxuan Chu
  • Xiaqing Li
  • Xuanbo Tong
  • Yong Zhao
  • Zhiquan Sun
    • 1
      Welcome & Registration
      Speaker: Anselm Vossen (Duke University/JLab)
    • TMDs: Session I

      Zoom recordings:
      first session:
      second session:

      • 2
        Theory and phenomenology of TMDs: progress and open questions

        In this talk I will briefly address the state of the art for our understanding of transverse-momentum-dependent distributions. I will also introduce some of the topics which are currently under investigation and highlight the fundamental role of the present experimental facilities for the advancement of the field.

        Speaker: Andrea Signori (University of Pavia and Jefferson Lab)
      • 3
        COMPASS results on upol TMDs
        Speaker: Andrea Moretti
      • 4
        TMDs: PDF bias and flavour dependence

        TMDs match collinear PDFs in the limit of small transverse distances. We study the bias on the TMD extraction caused by the choice of the PDF set. The bias is reduced by introducing a flavour dependence on the TMD profile and taking into account the PDF uncertainty. Both points improve the agreement between theory and experiment and should be taken into account in future global analyses.

        Speaker: Ignazio Scimemi (Universdad Complutense Madrid)
      • 5
        Recent work on N3LL' Drell-Yan predictions with SCETlib
        Speaker: Johannes Michel (MIT Center for Theoretical Physics)
    • 10:40 AM
    • TMDs: Session II

      Zoom recordings:
      first session:
      second session:

      • 6
        TMD extraction from COMPASS
        Speaker: Anna Martin (Trieste University & INFN)
      • 7
        Azimuthal correlations in dijet events at NLO with the parton branching method

        The azimuthal correlation of high transverse momentum jets in collisions at 13 TeV is studied by applying PB-TMD distributions to NLO calculations via MCatNLO together with the PB-TMD parton shower in Cascade3. A very good description of the cross section as a function of the azimuthal correlation is observed. In the back-to-back region, a very good agreement is observed with the PB-TMD Set 2 distributions while significant deviations are obtained with the PB-TMD Set 1 distributions. Set 1 uses the evolution scale while Set 2 uses transverse momentum as an argument in the strong coupling, and the above observation therefore confirms the importance of an appropriate soft-gluon coupling in angular ordered parton evolution. The total uncertainties of the predictions are dominated by the scale uncertainties of the matrix element, while the uncertainties coming from the PB-TMDs and the corresponding PB-TMD shower are very small. Measurements of the azimuthal correlation by CMS are also compared with predictions using MCatNLO together with PYTHIA8, illustrating the importance of details of the parton shower evolution.
        This talk is based on the recently published paper in Eur.Phys.J.C 82 (2022) 1, 36 (arXiv:2112.10465 [hep-ph]).

        Speaker: Mees van Kampen (University of Antwerp)
      • 8
        Matching TMD evolution with NLO matrix elements, Drell-Yan pT spectra at fixed-target and collider energies
        Speaker: A. Lelek
      • 9
        Evolution of twist-three TMD distributions

        The talk is devoted to the TMD distributions of twist-three and presents their systematic, evolution equations, small-b matching, and other properties. I explicitly demonstrate the non-trivial interplay between T-odd and T-even distributions and the presence of super-leading-power terms.

        Speaker: Alexey Vladimirov (Regensburg University)
    • 1:00 PM
    • Spin structure: Session I

      Zoom recording:

    • 3:15 PM
    • Spin structure: Session II

      zoom recording:
      (includes previous session)

    • GPDs: Session 1

      Recording Session I:

      Session II:

    • 10:15 AM
    • GPDs: Session II

      Recording Session I:

      Session II:

      • 19
        GPDs at JLab
        Speaker: Francois-Xavier Girod (UConn)
      • 20
        GPDs at COMPASS
        Speaker: Caroline Riedl (University of Illinois at Urbana-Champaign)
      • 21
        GPDs at EIC
        Speaker: Daria Sokhan (CEA Saclay (on leave from U. of Glasgow))
    • 12:10 PM
    • TMDs in medium: Session I


      • 22
        TMD in medium theory
        Speaker: John Terry (University of California, Los Angeles)
      • 23
        Di-hadron correlations in $e^-$A DIS with CLAS

        The CLAS Collaboration presents a measurement of the nuclear dependence of di-pion production in deep inelastic scattering off nuclei. We report results on the di-pion correlation functions (that is, the probability, given the detection of one hadron, of detecting a second hadron separated from the first by a given amount in azimuthal angle and rapidity) for charged pions.
        By making separate measurements for various targets ranging from deuterium to lead, our results complement earlier measurements which focused on nuclear-to-deuterium ratios of hadron yields.
        Our measurement is the first of its kind for nuclear DIS.
        The correlation functions increase with larger separation between the pions. However, this effect is less pronounced for heavier nuclei than for deuterium. This represents a new type of study in electron-nucleus collisions and serves as a pathfinder for future experiments with CLAS12 and the Electron-Ion Collider.

        Speaker: Sebouh Paul (UC Riverside)
      • 24
        MC generators for e-A measurements/eHIJING
        Speaker: Weiyao Ke (University of California, Berkeley; Lawrence Berkeley National Lab)
      • 25
        SRC theory, gluonic probes for SRC
        Speaker: Feng Yuan
      • 26
        Precision small-x physics at the EIC
        Speaker: Farid Salazar (UCLA/UCB/LBNL)
    • 3:05 PM
    • Target fragmentation: Session I


    • Hadronization: Session I

      recording session:

      second session:

    • 10:40 AM
    • Hadronization: Session II

      recording session:

      second session:

      • 35
        Monte Carlo simulation of the polarized hadronization process

        A complete Monte Carlo event generator capable of accounting for quark spin effects in hadronization and other stages of the event generation in a consistent way is still lacking. An essential prerequisite to reach this goal is a sound model of hadronization such as the quantum mechanical string+${}^3P_0$ model. The string+${}^3P_0$ model describes the polarized quark fragmentation process with production of pseudoscalar mesons and vector mesons. The detailed study of the model predictions is possible through the standalone Monte Carlo implementation of the model which, among others, allows to investigate still unknown effects such as the Collins effect for vector meson production and new transverse spin asymmetries arising in the decay of vector mesons. More quantitative simulations can be obtained by StringSpinner which provides an interface of the string+${}^3P_0$ model for pseudoscalar meson production with the Pythia event generator. In this talk we present the main results obtained from simulations with the string+${}^3P_0$ model and the comparison with the existing data on SIDIS and e+e- annihilation to hadrons.

        Speaker: Albi Kerbizi (INFN Trieste)
      • 36
        FFs at LHCb
        Speaker: Dr Sookhyun Lee (University of Michigan, Ann Arbor)
      • 37
        Di-hadron correlations
        Speaker: Christopher Dilks (Duke University)
      • 38
        Phenomenological extraction of a universal TMD Fragmentation Functions from BELLE data
        Speaker: Mariaelena Boglione (University of Turin and INFN Torino)
    • 1:00 PM
    • Nuclear: Session I


      • 39
        Initial and final state effects in the collinear approach

        In this talk I will give a brief overview of the current status of the nuclear modifications in PDFs and FFs.

        Speaker: Maria Zurita (University of Regensburg)
      • 40
        New Opportunities on Semi-inclusive Processes from $^3$He at CLAS12 JLab

        One of the central goals of nuclear and particle physics is to understand the internal dynamics of nucleons in terms of quarks and gluons, the fundamental degrees of freedom of quantum chromodynamics. The semi-inclusive deep inelastic scattering (SIDIS) is a golden channel to access the three-dimensional imaging and the spin structure of the nucleon. For neutron studies, a spin polarized $^3$He target has been widely used for decades as an effective polarized neutron target. Recently, a program of spin-dependent electron scattering from polarized $^3$He has been proposed at the CLAS12 spectrometer at Jefferson Lab with a novel polarized $^3$He target being developed. This talk will present the details of the proposed experiment and discuss the new opportunities on the SIDIS measurement on $^3$He at CLAS12.

        *This work is supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract No. DE-FG02-94ER40818 and DE-AC05-06OR23177.

        Speaker: Xiaqing Li (MIT)
      • 41
        Color transparency
        Speaker: Holly Szumila-Vance (JLab)
    • 3:35 PM
    • Radiative corrections: Session I


      • 42
        Radiative corrections, exp.
        Speaker: Bishnu Karki (OU)
      • 43
        Radiative corrections theory I
        Speaker: Nobuo Sato (Jefferson Lab)
      • 44
        Radiative corrections theory II
        Speaker: Igor Akushevich (Duke University)
    • New experiments: Gluons: Session I


      • 45
        LHCspin project: status and perspectives
        Speaker: Pasquale Di Nezza
      • 46
        Gluon physics at SPD (JINR)
        Speaker: Alexey Guskov (Joint Institute for Nuclear Research)
      • 47
        Correlations between v(2) and multiplicity in the CGC approach

        We study the correlations between the second flow harmonic v(2) and multiplicity of produced particles using the dilute-dense approach to Color Glass Condensate (CGC). We find an interesting correlation structure which depends on the width of the bin in transverse momentum. The physics of this dependence is the crossover between. HBT - dominated and Bose Einstein dominated correlations as a function of the bin width.

        Speaker: Alexander Kovner (University of Connecticut)
      • 48
        Accessing the proton content via transverse-momentum-dependent gluon distributions

        We present exploratory analyses of the 3D gluon content of the proton via a study of polarized gluon TMDs at leading-twist, calculated in a spectator model for the parent nucleon. Our approach encodes a flexible parameterization for the spectator-mass density, suited to describe both moderate- and small-$x$ effects. We show preliminary results on the application of our gluon TMDs to reactions featuring the production of heavy-quarkonium states. All these developments are relevant in the investigation of gluon dynamics inside nucleons and nuclei, which represents a major goal of new-generation colliding machines, as the EIC, NICA-SPD, the HL-LHC and the FPF.

        Speaker: Francesco Giovanni Celiberto (ECT*/FBK Trento & INFN-TIFPA)
      • 49
        Hadron Structure as seen by the AMBER experiment
        Speaker: Catarina Quintans (LIP-Lisboa)
    • 11:05 AM
    • Colinear


      • 50
        Double inclusive gluon production in ultra-peripheral collisions

        We provide the first calculation of two-gluon production at mid-rapidity in ultra-peripheral collisions in the Color Glass Condensate framework. To estimate systematic uncertainty associated with poor understanding of the wave function of the nearly real photon, we consider two diametrically different models: the dilute quark-antiquark dipole approximation and a
        vector meson, in which color charge density is approximated by McLerran-Venugopalan model. In the experimentally relevant range, the target nucleus can be faithfully approximated by highly saturated state. This simplification enables us to perform efficient numerical simulations and extract the two-gluon correlation functions.

        Speaker: Haowu Duan (North Carolina State University)
      • 51
        Disentangling Long and Short Distances in Momentum-Space TMDs
        Speaker: Zhiquan Sun
      • 52
        Extraction of e(x), other higher twist topics
        Speaker: Aurore Courtoy (CINVESTAV)
      • 53
        Can low-pT pion induced Drell-Yan data constrain pion parton distributions?
        Speaker: Leonard Gamberg (Penn State Berks)
    • 1:15 PM
    • Lattice


      • 54
        Connecting Lattice and Continuum TMDs with Factorization
        Speaker: Iain Stewart (MIT)
      • 55
        TMDs on the lattice
        Speaker: Yong Zhao (Massachusetts Institute of Technology)
      • 56
        Gravitational form factors on the lattice
        Speaker: Daniel Hackett