36 research outputs found
Strangeness nuclear physics: a critical review on selected topics
Selected topics in strangeness nuclear physics are critically reviewed. This
includes production, structure and weak decay of --Hypernuclei, the
nuclear interaction and the possible existence of bound
states in nuclei. Perspectives for future studies on these issues are also
outlined.Comment: 63 pages, 51 figures, accepted for publication on European Physical
Journal
Hybrid and Conventional Mesons in the Flux Tube Model: Numerical Studies and their Phenomenological Implications
We present results from analytical and numerical studies of a flux tube model
of hybrid mesons. Our numerical results use a Hamiltonian Monte Carlo algorithm
and so improve on previous analytical treatments, which assumed small flux tube
oscillations and an adiabatic separation of quark and flux tube motion. We find
that the small oscillation approximation is inappropriate for typical hadrons
and that the hybrid mass is underestimated by the adiabatic approximation. For
physical parameters in the ``one-bead" flux tube model we estimate the lightest
hybrid masses ( states) to be 1.8-1.9~GeV for
hybrids, 2.1-2.2~GeV for and 4.1-4.2~GeV for . We also
determine masses of conventional mesons with to in this
model, and confirm good agreement with experimental -averaged multiplet
masses. Mass estimates are also given for hybrids with higher orbital and
flux-tube excitations. The gap from the lightest hybrid level () to the
first hybrid orbital excitation () is predicted to be ~GeV
for light quarks and ~GeV for . Both and
hybrid multiplets contain the exotics and ; in
addition the has a and the contains a . Hybrid
mesons with doubly-excited flux tubes are also considered. The implications of
our results for spectroscopy are discussed, with emphasis on charmonium
hybrids, which may be accessible at facilities such as BEPC, KEK, a Tau-Charm
Factory, and in production at hadron colliders.Comment: 39 pages of RevTex. Figures available via anonymous ftp at
ftp://compsci.cas.vanderbilt.edu/QSM/bcsfig1.ps and /QSM/bcsfig6.p
Study of J\psi decaying into \omega p \bar p
The decay is studied using a
event sample accumulated with the BES II detector at the Beijing
electron-positron collider. The decay branching fraction is measured to be
. No
significant enhancement near the mass threshold is observed, and an
upper limit of is determined at the 95% confidence level, where X(1860)
designates the near-threshold enhancement seen in the mass spectrum
in decays.Comment: 5 pages, 4 figure
Prospects for e+e- physics at Frascati between the phi and the psi
We present a detailed study, done in the framework of the INFN 2006 Roadmap,
of the prospects for e+e- physics at the Frascati National Laboratories. The
physics case for an e+e- collider running at high luminosity at the phi
resonance energy and also reaching a maximum center of mass energy of 2.5 GeV
is discussed, together with the specific aspects of a very high luminosity
tau-charm factory. Subjects connected to Kaon decay physics are not discussed
here, being part of another INFN Roadmap working group. The significance of the
project and the impact on INFN are also discussed. All the documentation
related to the activities of the working group can be found in
http://www.roma1.infn.it/people/bini/roadmap.html.Comment: INFN Roadmap Report: 86 pages, 25 figures, 9 table