10,391 research outputs found
LHCb pentaquarks in constituent quark models
The recently discovered and states at LHCb have
masses close to the and thresholds,
respectively, which suggest that they may have significant meson-baryon
molecular components. We analyze these states in the framework of a constituent
quark model which has been applied to a wide range of hadronic observables,
being the model parameters, therefore, completely constrained.
The and are studied as molecular states composed
by charmed baryons and open charm mesons. Several bound states with the proper
binding energy are found in the and
channels. We discuss the possible assignments of these states from their decay
widths. Moreover, two more states are predicted, associated with the and thresholds.Comment: 5 pages, 2 table
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
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
Tunable entanglement distillation of spatially correlated down-converted photons
We report on a new technique for entanglement distillation of the bipartite
continuous variable state of spatially correlated photons generated in the
spontaneous parametric down-conversion process (SPDC), where tunable
non-Gaussian operations are implemented and the post-processed entanglement is
certified in real-time using a single-photon sensitive electron multiplying CCD
(EMCCD) camera. The local operations are performed using non-Gaussian filters
modulated into a programmable spatial light modulator and, by using the EMCCD
camera for actively recording the probability distributions of the
twin-photons, one has fine control of the Schmidt number of the distilled
state. We show that even simple non-Gaussian filters can be finely tuned to a
~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure
A Statistical Prescription to Estimate Properly Normalized Distributions of Different Particle Species
We describe a statistical method to avoid biased estimation of the content of
different particle species. We consider the case when the particle
identification information strongly depends on some kinematical variables,
whose distributions are unknown and different for each particles species. We
show that the proposed procedure provides properly normalized and completely
data-driven estimation of the unknown distributions without any a priori
assumption on their functional form. Moreover, we demonstrate that the method
can be generalized to any kinematical distribution of the particles
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