183 research outputs found
Radiative decays: a new flavour filter
Radiative decays of the orbital excitations of the ,
and to the scalars , and are shown to
provide a flavour filter, clarifying the extent of glueball mixing in the
scalar states. A complementary approach to the latter is provided by the
radiative decays of the scalar mesons to the ground-state vectors ,
and . Discrimination among different mixing scenarios is strong.Comment: 12 pages, 1 table, 0 figure
Charmonium Hybrid Production in Exclusive B Meson Decays
Recent data on charmonium production in B-meson decays suggest that
charmonium hybrid mesons with mass ~4 GeV may be produced in B-decay via
c\bar{c} colour octet operators. Some of these states are likely to be narrow
with clean signatures to J/\psi pi^+ pi^- final states. Experimental signatures
and search strategies for existing B-factories are described.Comment: references added and some of the text rewritten so it is cleare
Canonical Interpretation of the D_{sJ}(2860) and D_{sJ}(2690)
The spectrum and decay properties of radially excited states are
examined in a new model. Good agreement is obtained with the properties of two
recently announced mesons identified as and
as a possible mixture of and
. Searching for these mesons in B decays is advocated due to
large predicted branching ratios.Comment: 6 pages, 2 ps figures, revte
Radiative Scalar Meson Decays in the Light-Front Quark Model
We construct a relativistic wavefunction for scalar mesons within the
framework of light-front quark model(LFQM). This scalar wavefunction is used to
perform relativistic calculations of absolute widths for the radiative decay
processes, and
which incorporate the effects of glueball-
mixing. The mixed physical states are assumed to be ,and
for which the flavor-glue content is taken from the mixing
calculations of other works. Since experimental data for these processes are
poor, our results are compared with those of a recent non-relativistic model
calculation. We find that while the relativistic corrections introduced by the
LFQM reduce the magnitudes of the decay widths by 50-70%, the relative
strengths between different decay processes are fairly well preserved. We also
calculate decay widths for the processes and
(0^{++})\to\gamma\gamm involving the light scalars and
to test the simple model of these mesons. Our results of
model for these processes are not quite consistent with well-established data,
further supporting the idea that and are not conventional
states.Comment: 10 pages, 4 figure
Hybrid Decays
The heavy quark expansion of Quantum Chromodynamics and the strong coupling
flux tube picture of nonperturbative glue are employed to develop the
phenomenology of hybrid meson decays. The decay mechanism explicitly couples
gluonic degrees of freedom to the pair produced quarks and hence does not obey
the well known, but model-dependent, selection rule which states that hybrids
do not decay to pairs of L=0 mesons. However, the nonperturbative nature of
gluonic excitations in the flux tube picture leads to a new selection rule:
light hybrids do not decay to pairs of identical mesons. New features of the
model are highlighted and partial widths are presented for several low lying
hybrid states.Comment: 13 pages, 1 table, revte
Possible Molecular States of System and Y(4140)
The interpretation of Y(4140) as a molecule is studied
dynamically in the one boson exchange approach, where , and
exchange are included. Ten allowed states with
low spin parity are considered, we find that the , ,
, and configurations are most
tightly bound. We suggest the most favorable quantum numbers are
for Y(4140) as a molecule, however,
and can not be excluded. We propose to search for the
and partners in the and final
states, which is an important test of the molecular hypothesis of Y(4140) and
the reasonability of our model. The molecule is
deeply bound, experimental search in the channel at Tevatron
and LHC is suggested.Comment: 13 pages,2 figure
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
The newly observed open-charm states in quark model
Comparing the measured properties of the newly observed open-charm states
D(2550), D(2600), D(2750), D(2760), D_{s1}(2710), D_{sJ}(2860), and
D_{sJ}(3040) with our predicted spectroscopy and strong decays in a constituent
quark model, we find that: (1) the D(2\,^1S_0) assignment to D(2550) remains
open for its too broad width determined by experiment; (2) the D(2600) and
can be identified as the 2\,^3S_1-1\,^3D_1 mixtures; (3) if
the D(2760) and D(2750) are indeed the same resonance, they would be the
D(1\,^3D_3); otherwise, they could be assigned as the D(1\,^3D_3) and
, respectively; (4) the could be either the
's partner or the D_s(1\,^3D_3); and (5) both the
and interpretations for the seem likely. The
and radiative decays of these sates are also studied. Further
experimental efforts are needed to test the present quarkonium assignments for
these new open-charm states.Comment: 26 pages,7 figures, journal versio
Study of the , , and in the radiative decays
In this paper we present an approach to study the radiative decay modes of
the into a photon and one of the tensor mesons ,
, as well as the scalar ones and .
Especially we compare predictions that emerge from a scheme where the states
appear dynamically in the solution of vector meson--vector meson scattering
amplitudes to those from a (admittedly naive) quark model. We provide evidence
that it might be possible to distinguish amongst the two scenarios, once
improved data are available.Comment: The large Nc argument improved; version published in EPJA
The new analysis of the KLOE data on the phi->eta pi0 gamma decay
In this paper we present the fit to the recent high-statistical KLOE data on
the phi -> eta pi^0 gamma decay. This decay mainly goes through the a_0 gamma
intermediate state. The obtained results differ from those of the previous
fits: data prefer a high a_0 mass and a considerably large a_0 coupling to the
K\bar K}.Comment: 11 pages, 2 figure
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