22 research outputs found
Meson effective mass in the isospin medium in hard-wall AdS/QCD model
We study a mass splitting of light vector, axial-vector and pseudoscalar
mesons in isospin medium in the framework of hard-wall model. We write an
effective mass definition for the interacting gauge fields and scalar field
introduced in gauge field theory in the bulk of AdS space-time. Relying on
holographic duality we obtain a formula for the effective mass of a boundary
meson in terms of derivative operator over the extra bulk coordinate. The
effective mass found in this way coincides with the one obtained from finding
of poles of the two-point correlation function. In order to avoid introducing
distinguished infrared boundaries in the quantisation formula for the different
mesons from the same isotriplet we introduce extra action terms at this
boundary, which reduces distinguished values of this boundary to the same
value. Profile function solutions and effective mass expressions were found for
the in-medium , and mesons.Comment: 28 pages, clarifications added, 3rd section changed, version accepted
for publication in EPJ
Energy spectrum of simply constant chromoelectric flux tubes
In this article we obtain the energy spectrum of colored, spinor particles in
chromoelectric flux tubes. The chromoelectric field of the flux tubes
considered here comes from {\em simply} constant gauge potentials rather than
from covariantly constant gauge potential, as is usually the case. The energy
spectrum of the simply constant flux tubes is different than that of the
covariantly constant flux tubes. The spectrum is discrete due to the walls of
the tube and with a plus/minus constant shift depending on the magnitude of the
constant chromoelectric background. This goes against the classical intuition
where one would expect a charged particle in a uniform "electric" field to
accelerate with ever increasing velocity/energy i.e. there would be no constant
energy eigenvalue.Comment: 13 pages revtex, references added, introduction and discussion
sections revise
Vector Meson Gravitational Form Factors and Generalized Parton Distributions at finite temperature within the soft-wall AdS/QCD Model
We investigate the vector meson's gravitational form factors (GFFs) and
generalized parton distributions (GPDs) at finite temperatures within the
soft-wall AdS/ QCD model. The plotted soft-wall GFFs graphs at zero temperature
are close to the hard-wall results [1]. The dependence on temperature of the
GFFs and GPDs is studied using the thermal dilaton approach in the soft-wall
model. Plots of thermal GFFs show that they decrease in temperature increase.
Also, the gravitational radius of meson decreases in temperature growth
and becomes zero around the critical temperature . GPDs at
zero skewness are plotted and analyzed at zero and finite temperature cases.Comment: 17 pages, 8 figures, typos corrected, text slightly shortene
Electromagnetic transition form factors of nucleons from the hard-wall AdS/QCD model
The electromagnetic transition form factors for the transition between the
ground and excited states of nucleons are studied in the framework of the
hard-wall model of AdS/QCD. The profile functions of the spinor and vector
fields in the bulk of AdS space are presented. Using AdS/CFT correspondence
between the generating functions in the bulk and boundary theories an
expression for the transition form factors are obtained from the bulk action
for the interaction between the photon and nucleon fields. We consider the
R(1710, 1535, 1440)\rightarrow N transitions and plot the Dirac and Pauli form
factor dependencies on transferred momentum square. Also, the spiral amplitudes
for these transitions are presented.Comment: 19 pages, 16 figure