480 research outputs found
Relativistic Unitarized Quark/Meson Model in Momentum Space
An outline is given how to formulate a relativistic unitarized constituent
quark model of mesons in momentum space, employing harmonic quark confinement.
As a first step, the momentum-space harmonic-oscillator potential is solved in
a relativistically covariant, three-dimensional quasipotential framework for
scalar particles, using the spline technique. Then, an illustrative toy model
with the same dynamical equations but now one and one meson-meson
channel, coupled to one another through quark exchange describing the
mechanism, is solved in closed form on a spline basis. Conclusions are
presented on how to generalize the latter to a realistic multichannel
quark/meson model.Comment: Plain LaTeX, 12 pages, 2 EPS figures. Contribution to the Second
International Workshop on Hadron Physics, Effective Theories of Low Energy
QCD, 25-29 September, 2002 (Coimbra, Portugal
Comment on "Study of D(sJ) decays to D(*)K in inclusive e(+)e(-) interactions"
We comment on the recent observation of the decay mode D(sJ)(*)(2860)-->D(*)K
by the BABAR Collaboration [arXiv:0908.0806], and contest their peremptory
conclusion that the data exclude a 0(+) assignment for the D(sJ)(*)(2860). In
particular, we argue that the observed branching fraction
B(D(sJ)(*)(2860)-->D(*)K)/B(D(sJ)(*)(2860)-->DK)=1.1 pm 0.15 pm 0.19 supports
the existence of two largely overlapping resonances at about 2.86 GeV, namely a
pair of radially excited tensor 2(+) and scalar 0(+) c-sbar states. This
scenario is further justified by comparing with the corresponding excited
charmonium states. Also other aspects of the charm-strange spectrum are
discussed.Comment: regular LaTeX, 4 page
Modified Breit-Wigner formula for mesonic resonances describing OZI decays of confined states and the light scalar mesons
A general expression resembling Breit-Wigner formulae is derived for the
description of resonances which appear in meson-meson scattering. Starting
point is a unitarised meson model, but reduced to a simpler form and freed from
the specific assumption about the confining force. The parameters of the
resulting ``Resonance-Spectrum Expansion'' are directly related to the
confinement spectrum and the mechanism of valence-quark-pair creation
for OZI-allowed hadronic decay, and not to the central positions and widths of
resonances. The method also provides a straightforward explanation for the
origin of the light scalar mesons without requiring extra degrees of freedom.Comment: 21 pages, 6 figures included. v2, new figures with respect to the
movement of singularities in the complex energy plane. Discussion on model
dependence included. More references included. v3/4 extension
acknowledgements. v5, correction misspelling in citation to Karabarbounis and
Shaw's wor
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