73 research outputs found
Wigner distributions for an electron
We study the Wigner distributions for a physical electron, which reveal the
multidimensional images of the electron. The physical electron is considered as
a composite system of a bare electron and photon. The Wigner distributions for
unpolarized, longitudinally polarized and transversely polarized electron are
presented in transverse momentum plane as well as in impact parameter plane.
The spin-spin correlations between the bare electron and the physical electron
are discussed. We also evaluate all the leading twist generalized transverse
momentum distributions (GTMDs) for electron.Comment: 27 pages, 18 figures, text modified, version accepted in Nuclear
Physics
Gravitational form factors and angular momentum densities in light-front quark-diquark model
We investigate the gravitational form factors (GFFs) and the longitudinal
momentum densities ( densities) for proton in a light-front quark-diquark
model. The light-front wave functions are constructed from the soft-wall
AdS/QCD prediction. The contributions from both the scalar and the axial vector
diquarks are considered here. The results are compared with the consequences of
a parametrization of nucleon generalized parton distributions (GPDs) in the
light of recent MRST measurements of parton distribution functions (PDFs) and a
soft-wall AdS/QCD model. The spatial distribution of angular momentum for up
and down quarks inside the nucleon has been presented. At the density level, we
illustrate different definitions of angular momentum explicitly for an up and
down quark in the light-front quark-diquark model inspired by AdS/QCD.Comment: 14 pages, 9 figures; version to appear in EPJ
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