21 research outputs found
Sivers and Asymmetries in Semi-inclusive Deep Inelastic Scattering in Light-front Holographic Model
The spin asymmetries in SIDIS associated with -odd TMDs are presented in a
light-front quark-diquark model of a proton. To incorporate the effects of the
final state interaction, the light front wave functions are modified to have a
phase factor which is essential to have Sivers or Boer-Mulders functions. The
Sivers and Boer-Mulder asymmetries are compared with HERMES and COMPASS data.Comment: 24 pages, 09 figure
Relating transverse structure of various parton distributions
We present the results of T-even TMDs in a light front quark-diquark model of
nucleons with the wave functions constructed from the soft-wall AdS/QCD
prediction. The relations amongst TMDs are discussed. The dependence
of the TMDs are compared with the -dependence of the GPDs. AdS/QCD wave
function provides an explanation behind the approximate and
factorization observed in lattice TMD calculations.Comment: 11 pages, 8 figures, modified extensively, added new results and
discusssion
Quark generalized TMDs at skewness and Wigner Distribution in boost invariant longitudinal space
The boost-invariant longitudinal space, defined by the parameter
can be studied from the Fourier transformation of
distributions over the conjugate variable skewness . We investigate quark
Wigner distributions in the space in dressed quark model and found
diffraction patterns that are analogous to the single slit experiment of light
in optics. The width of the central maxima varies with energy transfer to the
system and essentially behaves like a slit-width. Qualitatively similar
diffraction pattern is reported recently in other models. In this model, we
compute all the leading twist GTMDs with non-zero skewness for quarks which
provides Wigner distributions under Fourier transformation
Gluon Wigner Distributions in boost invariant longitudinal space
We present the gluon Wigner distributions in the boost invariant longitudinal
space. The boost-invariant longitudinal space is defined as
and is conjugate to the skewness variable
. We use the dressed quark model, where a high-energetic quark is dressed
by a gluon. This two-particle system has the advantage of addressing both the
gluon and the quark sectors. The different contributions in Wigner
distributions coming from different polarizations of gluon and the dressed
quark system are investigated
Angularity in Higgs boson decays via at NNLL accuracy
We present improved predictions of a class of event-shape distributions
called angularity for a contribution from an effective operator in
Higgs hadronic decay that suffers from large perturbative uncertainties. In the
frame of Soft-Collinear Effective Theory, logarithmic terms of the distribution
are resummed at NNLL accuracy, for which 2-loop constant of gluon-jet
function for angularity is independently determined by a fit to fixed-order
distribution at NLO corresponding to relative to
the born rate. Our determination shows reasonable agreement with value in a
thesis recently released. In the fit, we use an asymptotic form with a
fractional power conjectured from recoil corrections at one-loop order and it
improves the accuracy of determination in positive values of angularity
parameter . The resummed distribution is matched to the NLO fixed-order
results to make our predictions valid at all angularity values. We also discuss
the first moment and subtracted moment of angularity as a function of that
allow to extract information on leading and subleading nonperturbative
corrections associated with gluons.Comment: 33 pages, 12 figure
Gluon distributions in the proton in a light-front spectator model
We formulate a light-front spectator model for the proton incorporating the
gluonic degree of freedom. In this model, at high energy scattering of the
proton, the active parton is a gluon and the rest is viewed as a
spin- spectator with an effective mass. The light front wave
functions of the proton are constructed using a soft wall AdS/QCD prediction
and parameterized by fitting the unpolarized gluon distribution function to the
NNPDF3.0nlo data set. We investigate the helicity distribution of gluon in this
model. We find that our prediction for the gluon helicity asymmetry agrees well
with existing experimental data and satisfies the perturbative QCD constraints
at small and large longitudinal momentum regions. We also present the
transverse momentum dependent distributions (TMDs) for gluon in this model. We
further show that the model-independent Mulders-Rodrigues inequalities are
obeyed by the TMDs computed in our model.Comment: 14 pages, 7 figure