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 qqˉq\bar{q} 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 $^3P_0$ 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

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 $q\bar{q}$ and one meson-meson channel, coupled to one another through quark exchange describing the $^3P_0$ 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