34 research outputs found
Rotational Corrections to in the NJL Model and Charge Conjugation
We show that the rotational corrections to , derived using the
semiclassical quantization scheme in the NJL model, possess correct properties
under charge conjugation.Comment: 4 pages, revtex, no figures, final version published in
Phys.Rev.C52(1995)42
Electromagnetic form factors of the nucleon in the chiral quark soliton model
In this paper we present the derivation as well as the numerical results for
the electromagnetic form factors of the nucleon within the chiral quark soliton
model in the semiclassical quantization scheme. The model is based on
semibosonized SU(2) Nambu -- Jona-Lasinio lagrangean, where the boson fields
are treated as classical ones. Other observables, namely the nucleon mean
squared radii, the magnetic moments, and the nucleon-- splitting are
calculated as well. The calculations have been done taking into account the
quark sea polarization effects. The final results, including rotational
corrections, are compared with the existing experimental data, and they are
found to be in a good agreement for the constituent quark mass of about 420
MeV. The only exception is the neutron electric form factor which is
overestimated.Comment: 17 pages, 11 figures added as postscript files (uuencoded), RevTeX
format, no special macros, final version to appear in Nucl.Phys.A (1995
Do we expect light flavor sea-quark asymmetry also for the spin-dependent distribution functions of the nucleon?
After taking account of the scale dependence by means of the standard DGLAP
evolution equation, the theoretical predictions of the chiral quark soliton
model for the unpolarized and longitudinally polarized structure functions of
the nucleon are compared with the recent high energy data. The theory is shown
to explain all the qualitative features of the experiments, including the NMC
data for , , the Hermes and NuSea
data for , the EMC and SMC data for ,
and . Among others, flavor asymmetry of the longitudinally
polarized sea-quark distributions is a remarkable prediction of this model,
i.e., it predicts that with a sizable negative coefficient
(and ) in qualitative consistency with the recent
semi-phenomenological analysis by Morii and Yamanishi.Comment: 14pages, including 5 eps_figures with epsbox.sty, late
Chiral Symmetry and the Nucleon Structure Functions
The isospin asymmetry of the sea quark distribution as well as the
unexpectedly small quark spin fraction of the nucleon are two outstanding
discoveries recently made in the physics of deep-inelastic structure functions.
We evaluate here the corresponding quark distribution functions within the
framework of the chiral quark soliton model, which is an effective quark model
of baryons maximally incorporating the most important feature of low energy
QCD, i.e. the chiral symmetry and its spontaneous breakdown. It is shown that
the model can explain qualitative features of the above-mentioned nucleon
structure functions within a single framework, thereby disclosing the
importance of chiral symmetry in the physics of high energy deep-inelastic
scatterings.Comment: 20pages, LaTex, 5 Postscript figures A numerical error of the
original version was corrected. The discussion on the regularization
dependence of distribution functions has been added. A comparison with the
low energy-scale parametrization of Gloeck, Reya and Vogt has been mad
Magnetic moments of the SU(3) decuplet baryons in the chiral quark-soliton model
Magnetic moments of baryons are studied within the chiral quark soliton model
with special emphasis on the decuplet of baryons. The model is used to identify
all symmetry breaking terms proportional to . Sum rules for the
magnetic moments are derived. A ``model-independent'' analysis of the symmetry
breaking terms is performed and finally model calculations are presented, which
show the importance of the rotational corrections for cranking of
the soliton.Comment: 22 pages, RevTex. The final version accepted for publication in Phys.
Rev.