23,463 research outputs found
Hybrid Baryon Signatures
We discuss whether a low-lying hybrid baryon should be defined as a three
quark - gluon bound state or as three quarks moving on an excited adiabatic
potential. We show that the latter definition becomes exact, not only for very
heavy quarks, but also for specific dynamics. We review the literature on the
signatures of hybrid baryons, with specific reference to strong hadronic
decays, electromagnetic couplings, diffractive production and production in psi
decay.Comment: Talk at ``The Physics of Excited Nucleons'' (NSTAR2000), Newport
News, VA, 16-19 Feb. 2000. 8 pages, LaTe
Strong Decays of Hybrid Mesons from the Heavy Quark Expansion of QCD
We calculate the strong decays of hybrid mesons to conventional mesons for
all the lowest lying J^PC hybrids of flavour uu, dd, ss, cc and bb. A decay
operator developed from the heavy quark expansion of quantum chromodynamics is
employed. We show that the selection rule that hybrid mesons do not decay to
identical S-wave mesons, found in other models, is preserved. We predict decays
of charmonium hybrids, discuss decays of J^PC=1^-+ exotic isovector hybrids of
various masses, and interpret the \pi(1800) as a hybrid meson.Comment: 5 pages, LaTeX, 2 eps figures. Contribution to the Seventh
International Conference on Hadron Spectroscopy (HADRON '97), Brookhaven,
August 1997. In collaboration with Eric S. Swanson and Adam P. Szczepania
Hybrid Baryons
We review the status of hybrid baryons. The only known way to study hybrids
rigorously is via excited adiabatic potentials. Hybrids can be modelled by both
the bag and flux-tube models. The low-lying hybrid baryon is N 1/2^+ with a
mass of 1.5-1.8 GeV. Hybrid baryons can be produced in the glue-rich processes
of diffractive gamma N and pi N production, Psi decays and p pbar annihilation.Comment: Invited plenary talk presented at the ``9th International Conference
on the Structure of Baryons'' (BARYONS 2002), 3-8 March, Newport News, VA,
USA. 12 pages, 7 encapsulated postscript figures, LaTe
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