Prof.
James Vary
(Iowa State University)
5/14/18, 9:20 AM
Prof.
Martha Constantinou
(Temple University)
5/14/18, 9:45 AM
Dr
Fernanda Steffens
5/14/18, 11:30 AM
Prof.
Leonard Gamberg
(Penn State Berks)
5/14/18, 2:25 PM
Prof.
Paul Hoyer
(University of Helsinki)
5/14/18, 2:50 PM
A perturbative expansion for bound states starts with a lowest order approximation that has a non-perturbative wave function, with all powers in the coupling $\alpha$.
The distinction between lowest and higher orders is blurred since contributions of finite order in $\alpha$ may be assigned to either one. A criterion beyond powers of $\alpha$ is needed to fully define a perturbative expansion...
Dr
Vincent Mathieu
(JLab)
5/14/18, 5:00 PM
Chueng R. Ji
(North Carolina State University)
5/15/18, 8:30 AM
W. Polyzou
5/15/18, 8:55 AM
Prof.
Stanley Brodsky
(SLAC National Accelerator Laboratory, Stanford Univsersity)
5/15/18, 9:45 AM
Dr
Sophia Chabysheva
(University of Minnesota-Duluth)
5/15/18, 2:00 PM
We explore the convergence of the light-front coupled-cluster (LFCC) method in the context of two-dimensional quenched scalar Yukawa theory. This theory is simple enough for higher-order LFCC calculations to be relatively straightforward. The quenching is to maintain stability; the spectrum of the full theory with pair creation and annihilation is unbounded from below. The basic interaction...
Raza Sufian
(Jefferson Lab)
5/15/18, 2:00 PM
Recently, it has been shown that a class of coordinate-space-separated non-local hadronic matrix elements, computable directly in lattice QCD, can be factorized into parton distribution functions with calculable coefficients, in the same manner as the hadronic cross sections measured in an experiment [Phys.Rev.Lett. 120 (2018) no.2, 022003]. The pion and kaon, the lightest pseudo scalar...
Mr
Patrick Barry
(North Carolina State University)
5/15/18, 2:20 PM
Pions have long been associated with being the lightest bound state made of quarks, antiquarks and gluons (partons), as well as being the Goldstone boson produced from the breaking of effective chiral symmetry. In previous works, its parton distribution function (PDF) has been determined only by $\pi A$ Drell-Yan (DY) experiments such as E615 and NA10 done at Fermilab and CERN, respectively. ...
Prof.
Anna Stasto
(Penn State)
5/15/18, 2:20 PM
In this presentation we will discuss some interesting properties of the off-shell scattering amplitudes in the framework of the light-front perturbation theory. It is shown that certain recursion relation between tree level off-shell amplitudes in this formalism actually resums whole classes of graphs into a Wilson line. More precisely, we demonstrate a correspondence between the light-front...
Prof.
Tobias Frederico
(Instituto Tecnologico de Aeronautica)
5/15/18, 2:40 PM
We study a pion Bethe-Salpeter (BS) amplitude model in Minkowski space inspired by Lattice QCD results for the quark self-energy for space like momentum. The model is based on the assumption of the Godstone boson nature of the pion and the pseudoscalar BS vertex is chosen to match the scalar part of the self-energy. The model allows a Nakanishi representation of the BS ampliude and produce...
Piotr Kotko
(Institute of Nuclear Physics, PAN)
5/15/18, 2:40 PM
The MHV Lagrangian is the Yang-Mills Lagrangian quantized on the light
cone, where the two transverse gluonic degrees of freedom have been
canonically transformed to a set of new fields, in which the vertices
become a series of the maximally helicity violating (MHV) amplitudes
continued off-shell. The usage of the MHV vertices to construct
amplitudes is also known as the...
Dr
Arkadiusz Trawinski
(CEA-Saclay)
5/15/18, 3:00 PM
The expectation value of the quantum energy-momentum tensor (EMT) for an unpolarized proton target in the Breit frame can be matched with an anisotropic perfect fluid EMT. This matching offers the possibility of interpreting the EMT form factors in terms of the internal energy and transverse/radial pressure inside an unpolarized proton target.
The generalization of this result to a more...
Dr
Joao Pacheco de Melo
(Laboratório de Fisica Teórica e Computacional, LFTC, UCS)
5/15/18, 3:00 PM
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Pion off-shell electromagnetic form factors
J.~P.~B.~C.~de~Melo$^1$,~Tobias Frederico$^2$ and C.-R.~Ji$^3$
$^1$Laborat\'orio de F\'{\i}sica Te\'orica e Computacional-LFTC
\newline Universidade Cruzeiro do Sul, 01506-000, S\~ao Paulo, Brazil \\
$^2$Departamento de F\'\i sica, Instituto Tecnol\'ogico...
Mr
Jorge Henrique De Alvarenga Nogueira
(Instituto Tecnológico de Aeronáutica & 'La Sapienza' Università di Roma & INFN, Sezione di Roma)
5/15/18, 3:20 PM
The advent of approaches based on the Euclidean space for studying
hadron observables, such as lattice QCD and Schwinger-Dyson equations,
has been remarkable and responsible to produce important understanding
on the non-perturbative dynamical regime.
However, the quantum field theory formulation in Minkowski space has subtle and
essential signatures as, e.g., the ones related to...
Arun Tadepalli
(Rutgers University)
5/15/18, 3:20 PM
The Fermilab E906/SeaQuest is an experiment aimed at studying the anti-quark distributions in nucleons and nuclei. The experiment uses a 120 GeV proton beam extracted from the Main Injector at Fermilab to collide with various liquid and cryogenic targets to study a variety of physics topics ranging from light quark flavor asymmetry to the EMC effect in the nucleon sea. It takes advantage of...
Prof.
simonetta liuti
(university of virginia)
5/15/18, 4:10 PM
Electromagnetic interactions probe the Fourier transform of the quark-quark correlation function measuring the light cone distance traveled by the struck quark during the interaction, also known as Ioffe time. The small distance behavior of the correlation function can be determined by the first few moments calculated on the lattice while its large distance behavior, exceeding the proton size,...
Dr
Tianbo Liu
(JLab & Duke)
5/15/18, 4:10 PM
The structure of generalized parton distributions is determined from light-front holographic QCD up to a universal reparametrization function $w(x)$ which incorporates Regge behavior at small $x$ and inclusive counting rules at $x \to 1$. A simple ansatz for $w(x)$ which fulfills these physics constraints with a single-parameter results in precise descriptions of both the nucleon and the pion...
Alberto Accardi
(Hampton U. and Jefferson Lab)
5/15/18, 4:30 PM
A new set of TMD sum rules is derived by relating integrals of the semi-inclusive quark-quark correlator to the fully dressed quark propagator. A complete set of momentum sum rules is obtained for the quark-quark TMDs up to twist-3 level, and for quark-gluon-quark TMDs up to twist-2. The technique is then extended to di-quark TMDs. Applications to inclusive DIS and semi-inclusive...
Stanislaw D. Glazek
(Faculty of Physics, University of Warsaw)
5/15/18, 4:50 PM
The ridge effect observed in high multiplicity events in proton-proton scattering at LHC can be due to the collisions of flux tubes in the projectiles which are in turn related to the fundamental physics of color confinement. We discuss observable effects due to gluon string collisions in electron-proton and peripheral proton-proton scattering related to scattering of photons. In the former...
Mr
Juan Guerrero
(Hampton University/Jefferson Lab)
5/15/18, 4:50 PM
It has been recently proposed that PDFs can be studied directly using lattice QCD. Such studies require the evaluation of matrix of non-local operators. Since this was first proposed, there has been an intense investigation of all possible systematics except for the effects associated with the fact that lattice QCD is necessarily defined in a finite spacetime. In this talk, I present the first...
Joseph Karpie
(College of William and Mary)
5/15/18, 5:10 PM
The Direct calculation of x-dependent parton distribution functions (PDFs) are not possible using ab initio Euclidean-space Lattice QCD, due to their definitions in terms of light-cone coordinates. I present the recent Lattice QCD calculation of pseudo PDFs, a Lorentz invariant generalization of light cone PDFs. These Lorentz invariant functions can be calculated on a Euclidean lattice and...
Jean-Philippe Lansberg
(IPN Orsay - CNRS/IN2P3 - Paris-Saclay U.)
5/15/18, 5:10 PM
I will review the physics opportunities offered by the use of the multi-TeV proton LHC beam in the fixed-target mode with a polarised target.
Dr
David Richards
(Jefferson Lab)
5/15/18, 5:30 PM
The charge radius of the nucleon can be related to the slope of the
electromagnetic form factors at zero momentum transfer. Calculations
of the form factors using lattice QCD are typically obtained for a
discrete set of momenta $Q^2$, from which the charge radius can be
inferred. We present a method to compute the slope of electromagnetic
form factors directly, including at $Q^2 = 0$,...
Dr
Nodoka Yamanaka
(IPN Orsay)
5/15/18, 5:30 PM
We evaluate the gluon and charm parton distribution functions (PDFs) of the deuteron using light-front quantization together with the impulse approximation.
We use a nuclear wave function obtained by solving the nonrelativistic Schrödinger equation with the realistic Argonne v18 nuclear force; it is then convoluted with the proton PDF.
The resulting gluon distribution in the deuteron (per...
Jacob Ethier
(College of William and Mary/Jefferson Lab)
5/16/18, 8:55 AM
W. Broniowski
5/16/18, 9:20 AM
Dr
Timothy Hobbs
(Southern Methodist University)
5/16/18, 9:45 AM
Haiyan Gao
(Duke University)
5/16/18, 10:40 AM
Dr
Carlos Granados
(The George Washington University)
5/16/18, 11:05 AM
We study the transverse spatial distribution of orbital angular momentum (OAM) in the nucleon at peripheral distances b∼1/Mπ. Chiral EFT is used to compute the form factors of the energy-momentum tensor and their peripheral transverse densities, including the density associated with light-front orbital angular momentum. This density is represented in first–quantized form, as overlap integral...
Nobuo Sato
(UConn)
5/17/18, 8:55 AM
Dr
Hrayr Matevosyan
(CSSM, University of Adelaide)
5/17/18, 9:45 AM
Mr
Kamil Serafin
(University of Warsaw)
5/17/18, 11:05 AM
Hamiltonian for baryons in heavy-flavor QCD is approximately
evaluated using the renormalization group procedure for
effective particles (RGPEP). The calculation
yields Hamiltonian terms up to second order in the strong coupling
constant. The renormalized Hamiltonian eigenvalue problem is
reduced to the Fock sector of only three quarks using assumption
that effective gluons develop...
Dr
Giovanni Salme'
(Istituto Nazionale di Fisica Nucleare -)
5/17/18, 2:00 PM
The formalism based on the Poincare' covariant spin-dependent spectral function, recently introduced [1] within the light-front (LF) Hamiltonian dynamics, allows one to develop a
phenomenological tool for investigating three-fermion bound systems, in particular their dynamical observables. As it
is well-known, several and quite
relevant efforts are underway at JLAB with the aim of...
Prof.
Matthias Burkardt
(NMSU)
5/17/18, 2:00 PM
Twist-3 Generalized Parton Distributions may provide an alternative source of information on quark orbital angular momentum. Additionally, twist-3 GPDs embody information on the spatial distribution of quark-gluon correlations and thus provide information about the transverse position dependence of forces that act on the active quark in a DIS experiment. We discuss both the connection between...
Dr
Mohammad Hattawy
(Argonne National Lab)
5/17/18, 2:20 PM
A wealth of information on the structure of matter lies in the correlations between the momentum and spatial distributions of the fundamental constituents of matter: quarks and gluons. These correlations are accessible via the study of generalized parton distributions (GPDs). The deeply-virtual Compton scattering (DVCS) is the preferred probe of GPDs and has been used to study the proton in a...
Dr
Chandan Mondal
(Institute of Modern Physics, Chinese Academy of Sciences)
5/17/18, 2:20 PM
Basis Light-front Quantization (BLFQ) has been proposed as a nonperturbative framework for solving quantum field theory. Based on the resulting light-front wave function obtained within the BLFQ framework, we investigate the several aspects of the nucleon properties such as electromagnetic form factors, generalized parton distributions (GPDs) etc.. In the effective Hamiltonian, we implement a...
Dr
Shaoyang Jia
(Department of Physics and Astronomy, Iowa State University)
5/17/18, 2:40 PM
We propose an effective Hamiltonian for the valance Fock sectors of mesons to implement the chiral quark condensate based on the Nambu-Jona-Lasinio model. Such a term allows us to generalize the basis light front quantization framework with the longitudinal confinement ansatz and the one-gluon exchange potential to the pi and rho mesons. The multi-flavor version of the effective Hamiltonian is...
Dr
Marat Siddikov
(Universidad Santa Maria)
5/17/18, 2:40 PM
We suggest that generalized parton distributions can be probed in charged current meson production process, $ep\to \nu_e\pi^{-}p$. In contrast to pion photoproduction, this process is sensitive to the unpolarized GPDs $H,E$, and for this reason has a very small contamination by higher twist and Bethe-Heitler type contributions. Since all produced hadrons are charged, we expect that the...
Mr
Colin Egerer
(William and Mary)
5/17/18, 3:00 PM
The axial charge of the nucleon remains a quantity of phenomenological importance as it relates to nuclear beta decay and the degree of chiral symmetry breaking in QCD. Defined simply as the axial vector form factor at zero momentum transfer, the axial charge of the nucleon has long been a benchmark calculation in Lattice Field Theory. The bulk of Lattice determinations of the nucleon axial...
Meijian Li
(Iowa State University)
5/17/18, 3:00 PM
We present calculations of radiative transitions between vector and pseudoscalar quarkonia in the light-front Hamiltonian
approach. The light-front wavefunctions of heavy quarkonia are obtained from the Basis Light-Front Quantization (BLFQ) approach
in a holographic basis. We study the transition form factor with both the traditionally used ``good current'' $J^+=J^0+J^z$ and the...
sirajudheen Kuthini Kunhammed
(The University of Iowa)
5/17/18, 3:20 PM
A class of Phenomenological models of hadronic systems motivated by QCD that have dual representations as a theory of quarks interacting with gluons and hadrons exchanging mesons are investigated. The model is formulated as a fully relativistic model with a light-front kinematic symmetry. The bare meson wave functions and production vertices are determined by the underlying QCD degrees of...
Alessandro Baroni
(University of South Carolina)
5/17/18, 3:20 PM
The non perturbative nature of QCD at low energies poses a challenge in
obtaining the properties of hadrons. LQCD has proven to be a useful tool for studying the structure of states that are stable under the strong interactions, which are a small fraction of the states present in QCD. In this talk, I will present efforts to study the structure of the majority of QCD states, which are either...
Ms
Bailing Ma
(North Carolina State University)
5/17/18, 4:10 PM
The fermion degrees of freedom in light-front dynamics (LFD) carry the unique constraint component distinguished from the ordinary equal-time fermion degrees of freedom. The constraint component of the fermion degrees of freedom in LFD results in the instantaneous contribution to the fermion propagator distinguished from the ordinary equal-time forward and backward propagation of relativistic...
Prof.
Ian Balitsky
(JLab/ODU)
5/17/18, 4:10 PM
A typical factorization formula for production of a particle with a small transverse momentum in hadron-hadron collisions is given
by a convolution of two TMD parton densities with cross section of production of the final particle by the two partons.
For practical applications at a given transverse momentum, though, one should estimate at what momenta
the power corrections to the TMD...
Ms
Shohini Bhattacharya
(Temple University)
5/17/18, 4:30 PM
Being the "mother distributions" of all types of two-parton correlation functions, generalized TMDs (GTMDs) have garnered a lot of attention. We address the important question of how to access GTMDs in physical processes. Recently, we have shown that quark GTMDs can in principle be probed through the exclusive pion-nucleon double Drell-Yan process, where the focus was on two particular GTMDs...
Dr
Jerzy Przeszowski
(University of Białystok)
5/17/18, 4:30 PM
In the canonical quantization procedure the quantum field operators are smeared with a test function of Schwartz class for coordinates on the quantization hypersurface, with a sharp dependence on the temporal parameter. Such quantum operators when acting on the vacuum state produce smeared 1-particle states and higher number particles states. These states, provided their norm is finite, form...
Dr
Anuradha Misra
(University of Mumbai)
5/17/18, 4:50 PM
An important issue in establishing the equivalence of
light-front QED in light cone gauge and the Covariant QED is the question of whether to use the two term or the three term propagator for the gauge boson. In this talk,
we elaborate on this issue and show, by way of examples, that the equivalence cannot be achieved without including the third term in the photon propagator.
Dr
Emanuel Ydrefors
(Instituto Tecnologico de Aeronautica)
5/17/18, 4:50 PM
From a general point of view, understanding the interaction in terms of the fundamental degrees of freedom is very important for nuclear and particle non-perturbative physics. Since that is a very difficult problem, simple models are of great value for understanding the crucial qualitative features of the solution with more realistic kernels. Understanding the properties of relativistic...
Lubomir Martinovic
(Institute of Physics SAS, Bratislava and BLTP JINR Dubna)
5/17/18, 5:10 PM
Recently, J. Collins has pointed out that vacuum diagrams are, contrary to the general belief, non-vanishing in light-front field theory. In our contribution, we first recall the old (forgotten) arguments by Chang and Ma and by Yan, why this should be so. Then we apply the
argument of analyticity of the self-energy diagrams in \lambda\phi^3 and \lambda \phi^4 two-dimensional models in...
Dr
Greger Torgrimsson
(Theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena; Helmholtz Institute Jena)
5/17/18, 5:10 PM
High-intensity lasers currently attract a great deal of interest due to the prospects of using them to study unexplored regimes of fundamental physics. Trident pair production is a basic process in this field, where an electron collides with a laser and produces an electron-positron pair. One part of this is a two-step process where the initial electron emits a real, on-shell photon that...
Frank Vera
(Florida International University)
5/17/18, 5:30 PM
We calculate the cross section of the electron scattering from a bound nucleon within light-front approximation.
The advantage of this approximation is the possibility of systematic account for the off-shell effects which become essential in high energy electro-nuclear processes aimed at probing the nuclear structure at small distances.
We derive a new dynamical parameter which allows to...
Dr
Henry Lamm
(University of Maryland)
5/17/18, 5:30 PM
A light-front quantization study of the nonperturbative
spectrum of the bound state $(\mu^+\mu^-)$, true muonium, has been
performed. Using Pad\'{e} approximants, it has been possible to
extract continuum and infinite-cutoff limits for the singlet and
triplet states for a range of coupling constants $\alpha$. This allows for an investigation of the $\alpha$ dependence of the...
Christian Weiss
(Jefferson Lab)
5/17/18, 5:50 PM
Measurements of deep-inelastic scattering (DIS) on polarized light ions (deuteron, 3He, ...) address important physics topics such as the spin structure of the neutron, nuclear modifications of parton densities, and coherent effects at small x. Detection of the nuclear breakup state ("spectator tagging") reveals the nuclear configurations present during the high-energy process and permits a...
Dr
Cedric Lorce
(Ecole polytechnique)
5/18/18, 8:30 AM
Dr
Cédric Mezrag
(INFN Sezione di Roma)
5/18/18, 8:55 AM
In the very few years after the introduction of Generalised Partons Distributions (GPDs), various authors have made attempts to compute the latter through the use of an overlap of Lightfront Wave Functions (LFWFs). However, contrary to Parton distribution functions (PDFs) or transverse momentum dependent functions (TMDs), GPDs are defined according to different overlaps on their definition...
Abha Rajan
(University of Virginia)
5/18/18, 9:20 AM
B. Bakker
5/18/18, 11:05 AM
Mr
Tanmay Maji
(Indian Institute of Technology Kanpur, Kanpur 208016, India)
5/18/18, 11:30 AM
Dr
Anselm Vossen
(Duke University)
5/18/18, 11:55 AM
Andre Walker-Loud
(LBNL)
5/18/18, 4:10 PM
Piet Mulders
(Vrije Universiteit Amsterdam, NIKHEF)
5/18/18, 5:00 PM
Ms
Nisha Dhiman
(Dr. B. R. Ambedkar National Institute of Technology, Jalandhar)
We study the quark distribution amplitudes $\phi_{M} (x)$ and decay constants of pseudoscalar and vector $B$ meson within the light-front framework. We apply the variational method to the QCD-motivated Hamiltonian with the Gaussian-type trial wave function to obtain the scale parameter $\beta$. After fixing the parameters, we obtain the numerical results for the corresponding decay constants....
Dr
Harleen Dahiya
(DR B.R. AMBEDKAR NATIONAL INSTITUTE OF TECH)
We have investigated the Wigner distributions and generalized transverse momentum-dependent distributions (GTMDs) in light-front quark-diquark model for the case of a scalar diquark. We have studied the Wigner distributions in the impact-parameter space, momentum space and mixed space for the case where quark is longitudinally polarized in the proton which has different polarization...
Mr
Tanmay Maji
(Indian Institute of Technology Kanpur, Kanpur 208016, India)
We present the leading twist T-odd generalized transverse momentum dependent parton distributions (GTMDs) $ F_{1,2} $ and $H_{1,1}$ of a quark dressed with gluon at one loop in perturbation theory. A nonvanishining T-odd GTMD requires gauge interactions which are incorporated as a Wilson line in the correlator. At the TMD limit ( $\Delta_\perp = 0$), $ F_{1,2} $ and $H_{1,1}$ reduce to the...
Dr
Carlos Granados
(The George Washington University)
We study the transverse spatial distribution of orbital angular momentum (OAM) in
the nucleon at peripheral distances $b\sim1/M_{\pi}$. Chiral EFT is used to compute
the form factors of the energy-momentum tensor and their peripheral transverse
densities, including the density associated with light-front orbital angular momentum.
This density is represented in first–quantized form, as...
Dr
Narinder Kumar
(Indian Institute of Technology Kanpur)
We present the results of the pion generalized parton distributions for non-zero skewness obtained from the overlap of light-front wavefunctions inspired by AdS/QCD. We consider the leading order $| q \bar{q} \rangle$ Fock state component of the pion state. We also calculate the charge density and gravitational form factor of the pion. Results provide the rich information on the internal...
