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Protection in the United States for “Famous Marks”: The Federal Trademark Dilution Act Revisited
Protection in the United States for “Famous Marks”: The Federal Trademark Dilution Act Revisited
Hypercentral constituent quark model and isospin dependence
The constituent quark model based on a hypercentral approach takes into
account three-body force effects and standard two-body potential contributions.
The quark potential contains a hypercentral interaction, to which a hyperfine
term is added. While the hypercentral potential supplies good values for the
centroid energies of the resonance multiplets and a realistic set of quark wave
functions, the hyperfine splittings are sometimes not sufficient to account for
the observed masses.
In this work we have introduced an improved form of the hyperfine interaction
and an isospin dependent quark potential. The resulting description of the
baryon spectrum is very good, also for the Roper resonance, specially thanks to
the flavour dependent interaction.Comment: 12 pages, 2 figures, accepted by Eur. Phys. J.
Extra S11 and P13 in the Hypercentral Constituent Quark Model
We report on the recent results of the hypercentral Constituent Quark Model
(hCQM). The model contains a spin independent three-quark interaction which is
inspired by Lattice QCD calculations and reproduces the average energy values
of the SU(6) multiplets. The splittings within each multiplet are obtained with
a SU(6)-breaking interaction, which can include also an isospin dependent term.
All the 3- and 4-stars resonances are well reproduced. Moreover, as all the
Constituent Quark models, the hCQM predicts ``missing'' resonances ({\em e.g.}
extra and states) which can be of some help for the experimental
identification of new resonances. The model provides also a good description of
the medium -behavior of the electromagnetic transition form factors. In
particular the calculated helicity amplitude for the
resonance agrees very well with the recent CLAS data. More recently, the
elastic nucleon form factors have been calculated using a relativistic version
of the hCQM and a relativistic quark current.Comment: 7 pages,3 figures, Talk given at NStar 2002 workshop on the physics
of excited nucleons, Pittsburgh, Pennsylvania, October 9-12, 200
Electromagnetic Form Factors and the hCQM
We briefly report on results about the electromagnetic form factors of the
nucleon obtained with different models and then we concentrate our attention on
recent results obtained with the hypercentral constituent quark model (hCQM).Comment: 12 pages, 5 figures, Invited talk at 27th Symposium on Nuclear
Physics, Taxco, Guerrero, Mexico, 5-8 Jan 200
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