93 research outputs found
Radiative decays of mesons in the NJL model
We revisit the theoretical predictions for anomalous radiative decays of
pseudoscalar and vector mesons. Our analysis is performed in the framework of
the Nambu-Jona-Lasinio model, introducing adequate parameters to account for
the breakdown of chiral symmetry. The results are comparable with those
obtained in previous approaches.Comment: 19 pages incl. 4 figure
Medium Effects in DIS from Polarized Nuclear Targets
The behavior of the nucleon structure functions in lepton nuclei deep
inelastic scattering, both polarized and unpolarized, due to nuclear structure
effects is reanalyzed. The study is performed in two schemes: an x-rescaling
approach, and one in which there is an increase of sea quark components in the
in medium nucleon, related to the low energy N-N interaction. In view of a
recent interesting experimental proposal to study the behavior of the proton
spin structure functions in nuclei we proceed to compare these approaches in an
effort to enlighten the possible phenomenological interest of such difficult
experiment.Comment: 11 pages and 5 figure
Quark masses without Yukawa hierarchies
A model based on the local gauge group SU(3)_c x SU(3)_L x U(1)_X without
particles with exotic electric charges is shown to be able to provide the quark
mass spectrum and their mixing, by means of universal see-saw mechanisms,
avoiding a hierarchy in the Yukawa coupling constants.Comment: 7 pages, 1 eps figure. Published in Europhysics Letter
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