2,739 research outputs found
Heavy mesons in the Quark Model
Since the discovery of the , the quark model was very successful in
describing the spectrum and properties of heavy mesons including only
components. However since 2003, with the discovery of the , many
states that can not be accommodated on the naive quark model have been
discovered, and they made unavoidable to include higher Fock components on the
heavy meson states. We will give an overview of the success of the quark model
for heavy mesons and point some of the states that are likely to be more
complicated structures such as meson-meson molecules.Comment: Contribution to the Proceedings of the 15th International Workshop on
Meson Physics - MESON201
A very broad X(4260) and the resonance parameters of the 3D vector charmonium state
We argue that the X(4260) enhancement contains a wealth of information on
vector c-cbar spectroscopy. We discuss the shape of the X(4260) observed in the
OZI-forbidden process "electron-positron into J/psi and a pair of charged
pions", in particular at and near vector charmonium resonances as well as
open-charm threshold enhancements. The resulting very broad X(4260) structure
does not seem to classify itself as a vector charmonium resonance, but its
detailed shape allows to identify new vector c-cbar states. Here, we estimate
the resonance parameters of the psi(3D) state.Comment: 4 pages, 5 figures; version 2: 2 figures replace
Puzzles in quarkonium hadronic transitions with two pion emission
The anomalously large rates of some hadronic transitions from quarkonium are
studied using QCD multipole expansion (QCDME) in the framework of a constituent
quark model which has been successful in describing hadronic phenomenology. The
hybrid intermediate states needed in the QCDME method are calculated in a
natural extension of our constituent quark model based on the Quark Confining
String (QCS) scheme. Some of the anomalies are explained due to the presence of
an hybrid state with a mass near the mass of the decaying resonance whereas
other are justified by the presence of molecular components in the wave
function. Some unexpected results are pointed out.Comment: Conference proceedings of the XI Quark Confinement and the Hadron
Spectrum (CONFINEMENT XI). Saint Petersburg (Russia) from 8 to 12 September
201
The X(3872) and other possible molecular states
We perform a coupled channel calculation of the and sectors
in the framework of a constituent quark model. The interaction for the
states is obtained using the Resonant Group Method (RGM) and the underlying
quark interaction model. The coupling with the two quark system is performed
using the model. The X(3872) is found as a molecular state with a
sizable component. A comparison with Belle and BaBar data has been
done, finding a good agreement. Other possible molecular molecular states are
discussed.Comment: 5 pages, 5 figures, Proceedings to the Hadron 2009 - XIII
International Conference on Hadron Spectroscopy, Florida State University
(USA
A 300 GHz "Always-in-Focus" Focusing System for Target Detection
A focusing system for a 300 GHz radar with 5 m target distance and 10 mm diameter spot size resolution is proposed. The focusing system is based on a Gaussian telescope scheme and its main parameters have been de¬signed using Gaussian beam quasi-optical propagation theory with an in-house developed MATLAB® based analysis tool. Then, this approach has been applied to a real focusing system based on two elliptical mirrors in order to reduce the distortion and cross-polar level and a plane mirror to provide scanning capabilities. The over¬all system has been simulated with a full-wave electromag¬netic simulator and its behavior is presented. With this approach, the focusing system always works "in-focus" since the only mirror that is rotated when scanning is the output plane mirror, so the beam is almost not distorted. The design process, although based in the well-known Gaussian beam quasi-optical propagation theory, provides a fast and accurate method and minimizes the overall size of the mirrors. As a consequence, the size of the focusing system is also reduced
Scaling of the 3P0 strength in heavy meson strong decays
The phenomenological 3P0 decay model has been extensively applied to
calculate meson strong decays. The strength \gamma\ of the decay interaction is
regarded as a free flavor independent constant and is fitted to the data. We
calculate through the 3P0 model the total strong decay widths of the mesons
which belong to charmed, charmed-strange, hidden charm and hidden bottom
sectors. The wave function of the mesons involved in the strong decays are
given by a constituent quark model that describes well the meson phenomenology
from the light to the heavy quark sector. A global fit of the experimental data
shows that, contrarily to the usual wisdom, the \gamma\ depends on the reduced
mass of the quark-antiquark pair in the decaying meson. With this
scale-dependent strength \gamma, we are able to predict the decay width of
orbitally excited B mesons not included in the fit.Comment: 7 pages, 5 tables, 2 figure
Nonleptonic decays and the nature of the orbitally excited charmed-strange mesons
The Belle Collaboration has recently reported a study of the decays and has given also estimates of relevant
ratios between branching fractions of decays
providing important information to check the structure of the
, and mesons. The
disagreement between experimental data and Heavy Quark Symmetry has been used
as an indication that and mesons could
have a more complex structure than the canonical one. We analyze
these ratios within the framework of a constituent quark model, which allows us
to incorporate the effects given by finite -quark mass corrections. Our
findings are that while the meson could have a sizable
non- component, the and mesons
seem to be well described by a pure structure.Comment: 13 pages, 1 figur
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