Light Cone 2022 Online: Physics of Hadrons on the Light Front



Chueng-Ryong Ji (North Carolina State University), Wayne Polyzou (The University of Iowa)

Light Cone 2022 is scheduled to be held via Zoom, UTC 1 pm - 4 pm, for September 19(M) – 23(F). 

We are very pleased to invite you to the Light Cone 2022 Online conference. Light Cone 2022 Online is the latest in the series of conferences that started
 in 1991 under the supervision of the International Light Cone Advisory Committee (ILCAC), which have played an important role in promoting research towards a rigorous description of hadrons and nuclei based on light-front quantization methods. As with earlier conferences in the series, the aim of this meeting will be to create a scientific program that will stimulate developments at the forefront of nuclear, hadron, and particle physics research. 

Physics Topics

  • Quantum field theory on the light front
  • Hadronic structure and nuclear structure in QCD 
  • Parton distribution functions
  • Few-body problems on the light front
  • Finite temperature and density QCD
  • Diffraction and small x physics
  • Meson and baryon resonances and exotic states 
  • The physics of electron ion colliders
  • Heavy flavor physics 
  • Spin physics
  • Light front holography
  • Structure of the light front vacuum 

This is an online (ZOOM) meeting and there is no registration fee. If you would like to attend the conference please fill out the free registration form that appears in the link below. Registration will ensure that you will be able to connect to the meeting via zoom.

The official time zone is UTC (or GMT).

  • Adam Freese
  • Ahmad Jafar Arifi
  • Alexandre Deur
  • Alfred Stadler
  • Andreas Metz
  • Anuradha Misra
  • Bailing Ma
  • Barbara Pasquini
  • Ben Bakker
  • Bernard Pire
  • Bheemsehan Gurjar
  • Bianca Maria Silveira de Oliveira
  • Brenda Miranda
  • Bruno El-Bennich
  • Bruno Mintz
  • Chandan Mondal
  • Chao Shi
  • Cheryl Henkels
  • Chris Leon
  • Chueng-Ryong Ji
  • Craig Roberts
  • Cédric Lorcé
  • Cédric Mezrag
  • Daniel Fagundes
  • Daniele Binosi
  • Daya Shankar Kulshreshtha
  • Daya Shankar Kulshreshtha
  • Deepasika Dayananda
  • Deepesh Bhamre
  • Dmitriy Kim
  • Dyana Duarte
  • Edgar Huayra Paitan
  • Eduardo Ferreira
  • Eli Piasetzky
  • Emanuel Katz
  • Emanuel Ydrefors
  • Enrique Ruiz Arriola
  • Enzo Benvenga
  • Erison Rocha
  • Fatiha Benmokhtar
  • Fernando Sobrinho
  • Francesco Giovanni Celiberto
  • Gabriel Rabelo Soares
  • Gabriel Silveira Ramos
  • Gerald Miller
  • Giovanni Salme'
  • Gláuber Sampaio dos Santos
  • Guangyao Chen
  • Guilherme Peccini
  • Guilherme Zeminiani
  • Gustavo Antônio Pires Vaccani
  • Gustavo Teixeira
  • Guy F. de Téramond
  • Göran Johansson
  • Haimon Trebien
  • Hiren Kakkad
  • Ho-Meoyng Choi
  • Hyeonja Jhang
  • James Vary
  • John Hiller
  • Jonatan Pantoja Paschoal
  • Joseph Maerovitz
  • João de Mello
  • João Vitor Lovato
  • Julio Cesar Chirichella Felicioni de Souza
  • Jurandi Leão
  • Kamil Serafin
  • Leonardo Di Giustino
  • Leonardo Moura
  • Leonardo Santos
  • Liuyuan Wen
  • Lubomir Martinovic
  • Lucas Moriggi
  • Lucas Pereira de Souza
  • Luciano Abreu
  • Magno Machado
  • Mairon Machado
  • Mamoon Sharaf
  • Mary Alberg
  • Matteo Rinaldi
  • Matěj Vaculčiak
  • Meijian Li
  • Mengyao Huang
  • Michael Kreshchuk
  • Michael Riberdy
  • Mitra Shabestari
  • Muhammad Fauzan Syahbana
  • Muhammad Ridwan
  • Oscar Adán Acevedo Sánchez
  • Patrick Barry
  • Paulo De Moura
  • Peter Lowdon
  • Philip Mannheim
  • Phoebe Sharp
  • Piet Mulders
  • Poonam Choudhary
  • Rafael Cardoso
  • Raj Kishore
  • Reinaldo Francener
  • Ricardo Fariello
  • Ríchard Terra
  • Sangyeong Son
  • Saurav Goyal
  • Sebastian Dawid
  • Sergio Scopetta
  • Sheila McCartor
  • Shohini Bhattacharya
  • shreeram jawadekar
  • Simone Venturini
  • Sophia Chabysheva
  • Sreeraj Nair
  • Stan Srednyak
  • Stanislaw Glazek
  • Stanley Brodsky
  • Sudeep Saha
  • Teresa Peña
  • Tiancai Peng
  • Tobias Frederico
  • Tulio Restrepo
  • Usha Kulshreshtha
  • Valerio Bertone
  • Valery Lyubovitskij
  • Victor Paulo Goncalves
  • Vladimir Karmanov
  • Wally Melnitchouk
  • Wayne de Paula
  • Wayne Polyzou
  • Wen-Chen Chang
  • Wenyang Qian
  • Werner Sauter
  • Wojciech Broniowski
  • Yang Li
  • Yongseok Oh
  • Yongwoo Choi
    • 1:00 PM 2:30 PM
      Session: 1
      Convener: Chueng-Ryong Ji (North Carolina State University)
      • 1:00 PM
        Insights into and contrasts between proton and pion structure 30m

        Parton distribution functions (DFs) are a preeminent source of hadron structure information; and experiments interpretable in terms of hadron DFs have long been a priority. For much of this time, DFs were inferred from global fits to data and viewed as benchmarks. Such fitting remains crucial, providing input for the conduct of numerous experiments worldwide. But the past decade has seen the dawn of a new theory era, with continuum and lattice studies of quantum chromodynamics beginning to yield robust DF predictions. This presentation will describe the first unified set of predictions for proton and pion DFs -- valence + glue + four-flavour-separated sea, and explain what their similarities and differences reveal about emergent hadron mass.

        Speaker: Craig Roberts (Nanjing Univ.)
      • 1:30 PM
        Dyson-Schwinger quark model with dynamical mass generation in Minkowski space 30m

        The Dyson-Schwinger equation is solved in Minkowski space for the quark propagator in a QCD-inspired model. In the rainbow-ladder truncation with a massive gluon and a Pauli-Villars regulator used to tune the infrared physics of the model, we show that it is possible to verify the realization of the dynamical chiral symmetry breaking in the large coupling regime. In this sense, the parameter set is chosen such that the gluon mass scale, the Pauli-Villars mass, and coupling constant are found by fitting the results for running quark mass and from the gluon mass suggested by lattice QCD calculations in the Landau gauge. Further extensions and the possibility to study a pion model within the Bethe-Salpeter framework with the self-energies in Minkowski space are also delineated.

        Speaker: Dyana C. Duarte (ITA, Brazil)
      • 2:00 PM
        Global QCD analyses of meson structures 30m

        The behavior of the valence quark PDF in the pion as the momentum fraction approaches 1 has been a long standing debate. The Jefferson Lab Angular Momentum (JAM) collaboration has tackled this problem by including both the historical fixed-target Drell-Yan (DY) data and the leading neutron (LN) electroproduction data from HERA in a simultaneous global QCD analysis. We have also introduced a systematic study of threshold resummation in the DY hard coefficients as well as the inclusion of reduced Ioffe time pseudo-distributions calculated from lattice data. Future measurements such as the 12 GeV JLab tagged deep inelastic scattering (TDIS) experiment as well as the complementary experiment at the anticipated electron-ion collider (EIC) may also be sensitive to the large momentum fraction behavior. In this talk I summarize the current JAM results as well as outline the potential impacts from the future facilities.

        Speaker: Patrick Barry (JLab)
    • 2:30 PM 2:45 PM
      Break 15m
    • 2:45 PM 4:15 PM
      Session: 2
      Convener: Chueng-Ryong Ji (North Carolina State University)
      • 2:45 PM
        Non-perturbative insights into the properties of particles at finite temperature 30m

        Local quantum field theory (QFT) provides a framework for establishing the non-perturbative constraints imposed on QFTs at non-vanishing temperatures. In this talk, I will outline how the locality of fields in particular has significant implications for understanding the phenomena experienced by particles as they move through a thermal medium. As an application, I will discuss how pion peak-broadening effects can be directly extracted from lattice QCD data, and why this is relevant for understanding the phase structure of QCD.

        Speaker: Peter Lowdon (Frankfurt Univ.)
      • 3:15 PM
        Nucleon structure: Knowns, known unknowns and unknown unknowns 30m

        I present a brief review of what I think is known and unknown about nucleon structure. One of the known unknowns is how the nuclear medium modifies the structure of the nucleon. The bulk of the talk is on a new model of the EMC effect based on Light-Front Holographic QCD (LFHQCD).

        Speaker: Gerald Miller (Univ. Washington)
      • 3:45 PM
        A light front perspective on the energy-momentum tensor 30m
        Speaker: Adam Freese (Univ. Washington)
    • 1:00 PM 2:30 PM
      Session: 3
      Convener: Stanislaw Glazek (University of Warsaw)
      • 1:00 PM
        Confinement, chiral symmetry breaking, holography and the 3D image of the pion 30m

        Confinement and chiral symmetry breaking are the two fundamental aspects of QCD in the non-perturbative regime. Yet, our understanding of the two remains incomplete to this date. In this talk, I will show how they can be understood within the semi-classical approach to QCD, light-front holography (LFH). I will further show that chiral symmetry breaking in LFH is consistent with a rigorous sum rule derived from the partially conserved axial-vector current (PCAC) and the general Lorentz structure of the pion. Within the same holographic model, the Goldstone boson shows some remarkable feature: it is mostly uniform within. The implication to ab initio LFQCD will also be mentioned.

        Speaker: Yang Li (UST, Hefei)
      • 1:30 PM
        Pion structure within a dynamical model in Minkowski space 30m

        In this talk I will discuss the pion structure within a dynamical model based on the solution of the Bethe-Salpeter equation in Minkowski space. Our analysis consider the pion as quark anti-quark bound state, interacting through a one-gluon exchange. The inputs of the model are the quark and gluon masses, and a scale parameter related to the extended quark-gluon vertex. Within this model, we obtain the full parton distribution function, its contribution due to light-front valence wave function and a comparison with experimental data, after the aplication of a NLO evolution[1]. We also present the unpolarized transverse-momentum dependent quark distributions. In addition, I will show that the model is able to compute other hadronic observables as pion weak decay constant, the valence probability, the LF-momentum distributions, the distribution amplitudes, the probability densities both in the LF-momentum space and the 3D space given by the Cartesian product of the covariant Ioffe-time and transverse coordinates [2]. Finally, we calculated the pion electromagnetic form factor with a good agreement with available experimental data [3].

        1. W. de Paula, E. Ydrefors, J. H. Alvarenga Nogueira, T. Frederico and G. Salme, Phys. Rev. D 105 (2022), L071505
        2. W. de Paula, E. Ydrefors, J. H. Alvarenga Nogueira, T. Frederico and G. Salme, Phys. Rev. D 103 (2021) no.1, 014002
        3. E. Ydrefors, W. de Paula, J. H. A. Nogueira, T. Frederico and G. Salme, Phys. Lett. B 820 (2021), 136494

        Speaker: Wayne de Paula (Instituto Tecnologico de Aeronautica)
      • 2:00 PM
        Nucleon with one dynamical gluon on the light front 30m

        We solve for the light-front wave functions of the nucleon from the light-front quantum chromodynamics (QCD) Hamiltonian, determined for their constituent three quarks and three quarks-gluon Fock components, together with a three-dimensional confinement. The eigenvectors of the light-front effective Hamiltonian provide a good quality description of the nucleon’s valence quark distribution functions following QCD scale evolution. We probe the nucleon’s gluon densities, helicity distribution and orbital angular momentum that constitutes the nucleon spin sum rule

        Speaker: Chandan Mondal (IMP,CAS, Lanzhou)
    • 2:30 PM 2:45 PM
      Break 15m
    • 2:45 PM 4:15 PM
      Session: 4
      Convener: Stanislaw Glazek (University of Warsaw)
      • 2:45 PM
        Structure and dynamics of the proton within a light-front model 30m

        Understanding the structure and dynamics of the proton constitute an important remaining challenges in hadron physics. From the theory side, one of the challenges is to extract from Lattice QCD calculations, performed in Euclidean space, Minkowskian quantities such as the proton parton distribution function. It is difficult to do the inversion of Euclidean quantities back to the corresponding Minkowskian ones, and thus important to have a solution defined directly in Minkowski space for calculations of dynamical observables such as momentum distributions. In this contribution we present results for the proton calculated using a simple although dynamical model defined in Minkowski space [1]. Our starting point is the Bethe-Salpeter-Faddeev equation for a system of three spin-less bosons interacting through a contact interaction. Recently, the general propertiies of the solution to this equation was studied in great detail by us in the papers [2, 3, 4]. In the present work, the equation is solved in the valence approximation (i.e. only the first Fock component is kept) and the parameters of the model are set by comparing the calculated Dirac form factor with experimental data. The single- and double parton distributions of the proton are then computed. The proton image in coordinate space in terms of the transverse coordinates and the Ioffe times \tilde{x}_{1,2} is also studied, by performing numerically the Fourier transformation of the distribution amplitude.

        [1] E. Ydrefors and T. Frederico, Phys. Rev. D (2021) 114012.
        [2] E. Ydrefors, J.H. Alvarenga Nogueira, V. Gigante, T. Frederico and V.A. Karmanov, Phys. Lett. B 770 (2017) 131.
        [3] E. Ydrefors, J.H. Alvarenga Nogueira, V.A. Karmanov and T. Frederico, Phys. Lett. B 791 (2019) 276.
        [4] E. Ydrefors, J.H. Alvarenga Nogueira, V.A.

        Speaker: Emanuel Ydrefors (IMP, CAS, Lanzhou)
      • 3:15 PM
        Basis-function approach to Quantum Chromodynamics of effective quarks 30m

        In the Hamiltonian formulation of QCD one faces many challenges. One of them is the fact that the Hilbert space is rich in structure with subspaces of varying number of particles and interactions that can easily change the number of particles. Another challenge lies in its singular interactions that need renormalization. I will talk about basis light front quantization (BLFQ) as a framework that is useful in dealing with the complexity of QCD Hilbert space and about renormalization group procedure for effective particles (RGPEP) as a method of obtaining renormalized Hamiltonians of QCD. Together, the two methods provide a tool for solving QCD. I will describe each method, highlight their strengths and limitations, argue how they can aid each other, and present the progress in combining them in a calculation of meson spectra.

        Speaker: Kamil Serafin (IMP, CAS, Lanzhou)
      • 3:45 PM
        The EMC effect within the light-front Hamiltonian dynamics 30m

        We present the description of hadronic three-body systems in valence approximation within a rigorous Light-Front approach [1,2]. The latter has been applied in particular to the analysis
        of electron deep inelastic scattering (DIS) on nuclear targets, in the valence region and in the Bjorken limit [3,4].
        The approach preserves Poincaré covariance, macroscopic locality, as well as number of particles and momentum sum rules. In this framework, the main theoretical ingredient is the LF nuclear spectral function properly related to the relative
        momentum distribution. This quantity has been used to realistically calculate the structure functions of the three-nucleon iso-doublet, very relevant for phenomenological studies in the present experimental scenario. At variance with previous light-front estimates for heavy nuclei, our analysis predicts a sizable European Muon Collaboration (EMC) effect,
        in fair agreement with available data. Notably, in the valence region, our results are rather independent with respect to the use of different parametrizations of the nucleon DIS structure functions and that of nuclear two- and three-body potentials [4].

        [1] "Light-Front spin-dependent Spectral Function and Nucleon Momentum
        Distributions for a Three-Body System"
        by A. Del Dotto, E. Pace, G. Salme', S. Scopetta
        Phys. Rev. C 95 (2017) 1, 014001 and arXiv:1609.03804 [nucl-th]
        [2] "Light-Front Transverse Momentum Distributions for J=1/2
        Hadronic Systems in Valence Approximation",
        by R. Alessandro, A. Del Dotto, E. Pace, G. Perna,
        G. Salme', S. Scopetta, Phys. Rev. C 104 (2021) 6, 065204 and arXiv:2107.10187
        [3] "EMC effect, few-nucleon systems and Poincaré covariance",
        by E. Pace, M. Rinaldi, G. Salme', S. Scopetta, Phys. Scr. 95 (2020) 064008
        and arXiv:2004.05877
        [4] E. Pace, M. Rinaldi, G. Salme', S. Scopetta, arXiv:2206.05485

        Speaker: Matteo Rinaldi (INFN, Perugia)
    • 1:00 PM 2:30 PM
      Session: 5
      Convener: James Vary (Iowa State University)
      • 1:00 PM
        Signature of gluon orbital angular momentum 30m

        By considering double spin asymmetry (DSA) in exclusive dijet production in ep collisions, we demonstrate for the first time that the cos($\phi$) angular correlation between the scattered electron and proton is a direct probe of the gluon orbital angular momentum and its interplay with the gluon helicity. We also make an estimate of the DSA for typical kinematics of the future Electron Ion Collider.

        Speaker: Shohini Bhattacharya (BNL)
      • 1:30 PM
        Interpolating ‘t Hooft model between the instant form dynamics and the light front dynamics 30m

        'T Hooft model, or QCD in one-plus-one dimension, is interpolated between the Instant Form Dynamics (IFD) and the Light Front Dynamics (LFD). The interpolation form is defined by introducing an interpolation angle $ \delta$ varying between $0^{\circ}$ (IFD) and $45^{\circ}$ (LFD). The mass gap equation is solved in the interpolation form and the results found to agree with the previously published results in the IFD and LFD forms as $\delta \to 0^{\circ}$ and $\delta \to 45^{\circ}$, respectively. We note that the zero mode in LFD makes up all the contribution to the difference between the bare and constituent quark masses. Wavefunction renormalized quark self energy function is defined, which resolves the previous issue that the quark self energy goes negative for a certain range of momentum for smaller quark masses. Chiral condensate is computed and found to be invariant no matter the $\delta$ value. Solving the bound state equation, meson spectroscopy and their wavefunctions are obtained, and we apply them to the calculation of quasi-PDFs. We note a possibility of using the interpolation angle dependence in addition to the frame dependence in approaching the LFD PDFs.

        Speaker: Bailing Ma (NCSU/ANL)
      • 2:00 PM
        Going to the light front with contour deformations 30m

        Hadrons are strongly interacting particles composed of quarks and gluons and described by Quantum Chromodynamics (QCD). Their internal structure can be described in terms of structure functions that encode, for example, the momentum and spin distributions of their constituents. Parton distribution functions (PDFs), for example, describe the quark and gluon momentum distributions inside a hadron. These distribution functions are, however, not easy to calculate, because they are defined on the light front, whereas most hadron calculations are performed in a Euclidean metric and yield, for instance, the hadron’s Bethe-Salpeter wave functions. The main problem is then to project these Bethe-Salpeter wave functions onto the light front. We present a new method to compute the light-front wave functions using contour deformations, which we illustrate for a simple system of two interacting scalar particles of equal mass. After solving the two-body Bethe-Salpeter equation, the projection onto the light front is done through a combination of contour deformations and analytic continuation methods. The resulting light-front wave functions and distribution amplitudes are in agreement with the Nakanishi method frequently used in the literature. We show that the contour deformation method can also be used for particles of unequal masses, as well as particles with complex conjugate propagators poles, to make contact with QCD. Finally, we explore ways of extending this method to the calculation of more general parton distributions, such as transverse momentum distributions (TMDs) and generalized parton distributions (GPDs).

        Speaker: Eduardo Ferreira (U. Lisboa)
    • 2:30 PM 2:45 PM
      Break 15m
    • 2:45 PM 4:15 PM
      Session: 6
      Convener: James Vary (Iowa State University)
      • 2:45 PM
        First multidimensional $ep \to e’p’X$ single spin asymmetries in the target fragmentation at Jefferson Lab. 30m

        Studies of the properties and the azimuthal distribution of hadrons produced in the Target Fragmentation Region serve as a test of our complete understanding of the different mechanisms in the Semi-Inclusive Deep Inelastic Scattering production of hadrons and provide additional information on the QCD dynamics that are not accessible with single hadron production in the Current Fragmentation Region. We present first Multi-dimensional studies of beam SSA for semi-inclusive protons (ep → e′p’X), produced in the TFR, that can be related to higher twist Fracture Functions prescribing the formation of protons out of the target remnant. The CLAS12 detector in Hall B at Jefferson lab collected data with a longitudinally polarized 10.6~GeV electron beam on an unpolarized hydrogen target. Preliminary results from these measurements captured the transition between the TFR and CFR regions showing a clear sign change of the SSA for protons produced in the backward region in CM, dominated by TFR protons providing a possible benchmark for the first experimental separation of CFR and TFR regions. These findings are opening a new avenue for studies of nucleon structure.

        Speaker: Fatiha Benmokhtar (Duquesne University)
      • 3:15 PM
        Light-front quantization of the fermionic vector Schwinger model 30m

        I would present the light-front quantization of the fermionic vector Schwinger Model using the formalism of so-called "good fermions and bad fermions" due to Mannheim and Mannheim, Lowdon and Brodsky.

        Speaker: Daya Shankar Kulshreshtha (University of Delhi)
      • 3:45 PM
        Light-front quantization of the Maxwell Chern-Simons Higgs theory under broken symmetry phase 30m

        In this talk, I would present the light-front quantization of the Maxwell Chern-Simons Higgs Theory under Broken Symmetry Phase using the Hamiltonian and Path Integral formulations.

        Speaker: Usha Kulshreshtha (University of Delhi)
    • 1:00 PM 2:30 PM
      Session: 7
      Convener: Barbara Pasquini (University of Pavia and INFN, Pavia)
      • 1:00 PM
        The QCD running coupling 30m

        We will discuss the QCD running coupling $\alpha_s$, starting from its pQCD definition and then show how it can be extended to the non-perturbative domain using the concept of effective charges. This permits us to measure $\alpha_s$ in the non-perturbative domain, and compute it in the Holographic LF QCD (HLFQCD) approach. We will briefly describe the calculation, compare its result to $\alpha_s$ measurements, as well as to independent calculations based on the Dyson-Schwinger equations. Finally, we will show how αs from HLFQCD permits us to determine the hadron mass spectrum using solely $\Lambda_{QCD}$ as input.

        Speaker: Alexandre Deur (Jefferson Lab)
      • 1:30 PM
        Emerging superconformal structure in holographic light-front QCD 30m

        A remarkable property of holographic light-front QCD (HLFQCD) is the emerging superconformal structure which is responsible for the introduction of a mass scale without leaving the conformal group. This symmetry also fixes the effective confinement potential and leads to a massless pion in the chiral limit, without additional assumptions. In this talk, I will briefly review some of these new developments which include also other important aspects of hadronic physics not explicitly apparent from the QCD Lagrangian, such as the pattern of hadronic excitations across particle families, and remarkable supersymmetric relations between the spectroscopy of mesons, baryons, and tetraquarks.

        Speaker: Guy F. de Teramond (Univ de Costa Rica)
      • 2:00 PM
        New results on gluon and heavy quark content in the nucleon 30m

        We apply Holographic QCD for study gluon and heavy quark content in the nucleon. In particular, we discuss the following results:

        (1) sum rules, small and large x-behavior for the gluon TMDs [1];

        (2) light-front representations and numerical results for the heavy quark-antiquark asymmetry, the electromagnetic form factors of nucleons induced by heavy quarks, including their magnetic moments and radii [2].

        [1] V. E. Lyubovitskij and I. Schmidt, Phys. Rev. D 104, 014001 (2021); Phys. Rev. D 103, 094017 (2021); Phys. Rev. D 102, 034011 (2020).

        [2] S. J. Brodsky, V. E. Lyubovitskij, and I. Schmidt, [arXiv:2209.00403 [hep-ph]].

        Speaker: Valery E. Lyubovitskij (Tubingen Univ.)
    • 2:30 PM 2:45 PM
      Break 15m
    • 2:45 PM 4:15 PM
      Session: 8
      Convener: Barbara Pasquini (University of Pavia and INFN, Pavia)
      • 2:45 PM
        Physics on and off the light cone 30m

        On the light cone the full symmetry is conformal symmetry not just Lorentz symmetry. Spontaneously breaking conformal symmetry gives masses to particles and takes them off the light cone. Canonical quantization specifies equal time commutators on the light cone. Instant time and light-front commutators are very different, but can be shown to be equivalent by looking at unequal time commutators. We discuss the connection of the light-front approach to the infinite momentum frame approach, and show that vacuum graphs are outside this framework. We show that there is a light-front structure to both AdS/CFT and the eikonal approximation.

        Speaker: Philip D. Mannheim (Univ. Connecticut)
      • 3:15 PM
        Virtual Compton scattering on ${}^4$He: Rosenbluth formula 30m

        In the present study, the phenomenology of deeply virtual Compton scattering (DVCS) is considered. It is a well-known fact that a charged spin zero hadron has five Compton form factors (CFFs), all of which contribute to the DVCS ampli- tude if the absorbed and emitted photons are virtual. If the emitted photon is real, the number of CFFs that contribute is reduced to three. This analysis is relevant for experiments on DVCS on 4He.
        It is important to be aware of the fact that the CFFs, unlike Generalized Parton Distributions, are Lorentz scalars. Therefore they can be studied in any kinematics. The work presented here analyses the behaviour of the CFFs for large Q. The contributions to the DVCS amplitude of the CFFs that are suppressed by powers of Q appear to be kinematically enhanced. Moreover, for medium values of Q, less than the mass of the 4He nucleus, for instance attainable at CEBAF, target mass effects are also important.
The Rosenbluth-type of representation of the cross sections is presented. As a
        benchmark, the beam-spin asymmetry at tree level is presented.

        Speaker: Ben Bakker (VU, Amsterdam)
      • 3:45 PM
        The pressure inside the proton: a NLO analysis 30m

        In this talk we will discuss the connection between available experimental data and the pressure anisotropy within the nucleon, pushing the formalism at next-to-leading order (NLO). We will discuss the feasibility of extracting quark and gluon contributions, and see how future experimental facilities can contribute.

        Speaker: Cedric Mezrag (IRFU, CEA, Saclay)
    • 1:00 PM 2:30 PM
      Session: 9
      Convener: Wayne Polyzou (The University of Iowa)
      • 1:00 PM
        Chiral anomaly and the pion properties in the light-front quark model 30m

        We explore the link between the chiral symmetry of QCD and the numerical results of the light-front quark model, analyzing both the two-point and three-point functions of the pion. Including the axial-vector coupling as well as the pseudoscalar coupling in the light-front quark model, we discuss the implication of the chiral anomaly in describing the pion decay constant, the pion-photon transition form factor and the electromagnetic form factor of the pion. In constraining the model parameters, we find that the chiral anomaly plays a critical role and the analysis of $F_{\pi\gamma}(Q^2)$ in timelike region is important. Our results indicate that the constituent quark picture is effective for the low and high $Q^2$ ranges implementing the quark mass evolution effect as $Q^2$ grows.

        Speaker: Ho-Meoyng Choi (Kyungpook National University)
      • 1:30 PM
        Mass sum rules for the nucleon 30m

        How to decompose the mass of a hadronic system in a meaningful way is a question that has been much debated in the last few years. We propose a nutshell summary of the various pictures, discussing their meaning, how they are related to each other, and how they can be measured.

        Speaker: Cédric Lorcé (Ecole Poly, CPHT)
      • 2:00 PM
        Computing GPDs in lattice QCD: Recent progress 30m

        Recent progress has enabled the approximate computation of light-cone correlation functions in lattice QCD by evaluating Euclidean correlation functions. We will briefly discuss those developments as well as their application to GPDs. We will also talk about our latest work where we developed a formalism that makes the lattice calculations of GPDs more efficient.

        Speaker: Andreas Metz (Temple Univ.)
    • 2:30 PM 2:45 PM
      Break 15m
    • 2:45 PM 4:15 PM
      Session: 10
      Convener: Wayne Polyzou (The University of Iowa)
      • 2:45 PM
        Quantum simulation: Cracking the exponential wall 30m

        The rapid development of quantum technologies enables the usage of quantum computers for studying various physical systems. For several reasons, the light-front (LF) formulation of QFT appears to be a natural starting point for simulating HEP on quantum devices. I will summarize the known results in quantum simulation of LF physics as well as review some ongoing projects, emphasizing the connection with recent theoretical advances in LF QFT.

        Speaker: Michael Kreshchuk (LBL)
      • 3:15 PM
        From time dependent correlation functions to thermalization: Using non-perturbative wavefunctions from LCT 1h

        Lightcone Conformal Truncation (LCT) is a Hamiltonian Truncation scheme which allows us to solve QFTs numerically. In particular, we can use it to determine eigenstate wavefunctions in the non-perturbative regime in both 2d and 3d QFTs. We use these to calculate time-dependent correlation functions in various models. These include 2d gauge theories near the chiral limit, as well as 2d and 3d theories near criticality. In addition, we use eigenstate wavefunctions to explore chaos and thermalization, finding evidence for the Eigenstate Thermalization Hypothesis.

        Speaker: Emanuel Katz (Boston University)