28 research outputs found
Quark Wigner Distributions Using Light-Front Wave Functions
The quasi-probabilistic Wigner distributions are the quantum mechanical
analog of the classical phase-space distributions. We investigate quark Wigner
distributions for a quark state dressed with a gluon, which can be thought of
as a simple composite and relativistic spin-1/2 state with a gluonic degree of
freedom. We calculate various polarization configurations, namely unpolarized,
longitudinally polarized and transversely polarized quark and the target state
using light-front wave functions in this model. At leading twist, one can
define 16 quark Wigner distributions, however, we obtain only 8 independent
non-zero Wigner distributions in our model. We compare our results with other
model calculations for the proton.Comment: 21 pages, 5 figures, version published by Phys. Rev.
Three Dimensional Imaging of the Nucleon
We study the Wigner distributions of quarks and gluons in light-front dressed
quark model using the overlap of light front wave functions (LFWFs). We take
the target to be a dressed quark, this is a composite spin state of
quark dressed with a gluon. This state allows us to calculate the quark and
gluon Wigner distributions analytically in terms of LFWFs using Hamiltonian
perturbation theory. We analyze numerically the Wigner distributions of quark
and gluon and report their nature in the contour plots. We use an improved
numerical technique to remove the cutoff dependence of the Fourier transformed
integral over .Comment: 7 pages, 2 figures, Prepared for Proceedings of Light Cone 2017,
18-22 Sept, University of Mumbai, India. To appear in FB
Wigner distributions of quarks for different polarizations
We calculate quark Wigner distributions using the light-front wave functions
in a dressed quark model. In this model, a proton target is replaced by a
simplified spin-1/2 state, namely a quark dressed with a gluon. We calculate
the Wigner distributions for different polarization configuration of quark and
the target state in this model.Comment: 6 pages, 12 figures. Presented by Jai More at Light Cone 2016, 5-8
September 2016, IST, Universidade de Lisboa, Portuga
Wigner Distributions For Gluons
We investigate the gluon Wigner distributions for unpolarized, longitudinally
polarized and transversely polarized target state. Instead of a nucleon, we
take the target state to be a quark dressed with a gluon at one loop and
investigate the gluon Wigner distributions at leading twist. Better numerical
convergence is obtained compared to an earlier study, that removes the
regulator dependence of the results. We present a first calculation of the
Wigner distribution for the transversely polarized target and linearly
polarized gluon. We study the spin densities in momentum and impact parameter
space. We also investigate the quark and gluon helicity and orbital angular
momentum distributions at small-.Comment: 27 pages, 10 figures, two figures added, replaced with the revised
version published in EPJ
Double parton distributions for a positronium-like bound state using light-front wave functions
We investigate the double parton distributions (DPDs) for a positronium-like
bound state using light-front QED. We incorporate the higher Fock three
particle component of the state, that includes a photon. We obtain the overlap
representation of the DPDs in terms of the three-particle light-front wave
functions (LFWFs). Our calculation explores the correlations between the
momentum fractions of the particles probed and the transverse distance between
them, without any assumption of factorization between them. We also investigate
the behavior of the DPDs near the kinematical boundary when the sum of the
momentum fractions is close to one.Comment: 16 pages, 5 figure
Sum rules for the Gravitational Form Factors using light-front dressed quark state
We consider a light-front dressed quark state, per se, instead of a proton
state, we consider a simple composite spin-1/2 state of a quark dressed with a
gluon. This perturbative model incorporates gluonic degrees of freedom, which
enable us to evaluate the gravitational form factors (GFFs) of the quark as
well as the gluon in this model \cite{More:2021stk, More:2023pcy}. We employ
the Hamiltonian framework and choose the light-front gauge . We
calculate the four GFFs and corroborate the sum rules that GFFs satisfy. The
GFF is attributed to information like pressure, shear, and energy
distributions. We analyze some of these distributions for a dressed quark state
at one loop in QCD.Comment: Presented by Jai More at the International Conference on the
Structure of Baryons, November 7-11th, Universidad Pablo de Olavide, Sevilla,
Spain. 8 pages, 3 figures. To appear in Few-Body system
Generalized parton distributions of gluon in proton: a light-front quantization approach
We solve for the gluon generalized parton distributions (GPDs) inside the
proton, focusing specifically on leading twist chiral-even GPDs. We obtain and
employ the light-front wavefunctions (LFWFs) of the proton from a light-front
quantized Hamiltonian with Quantum Chromodynamics input using basis light-front
quantization (BLFQ). Our investigation incorporates the valence Fock sector
with three constituent quarks and an additional Fock sector, encompassing three
quarks and a dynamical gluon. We examine the GPDs within impact parameter space
and evaluate the -dependence of the transverse square radius. We find that
the transverse size of the gluon at lower- is larger than that of the quark,
while it exhibits opposite behavior at large-. Using the proton spin sum
rule, we also determine the relative contributions of quarks and the gluon to
the total angular momentum of the proton.Comment: 10 pages, 4 figure
Photon Generalized Parton Distributions
We present a calculation of the generalized parton distributions of the
photon using overlaps of photon light-front wave functions.Comment: Talk given at LightCone 2011, 4 pages, 3 figure