1,730 research outputs found
B decays to excited charm mesons
We review several aspects of the phenomenology of P-wave mesons:
mass splittings, effective strong couplings and leptonic constants. We also
describe a QCD sum rule determination to order of the form factor
governing the semileptonic decays to the charm doublet with
.Comment: LaTex, 3 pages, 1 figure. Talk given at 3rd International Conference
on Hyperons, Charm and Beauty Hadrons, Genoa, Italy, 30 Jun - 3 Jul 199
Configurational Entropy can disentangle conventional hadrons from exotica
We evaluate the Configurational Entropy (CE) for scalar mesons and for
baryons in a holographic approach, varying the dimension of
boundary theory operators and using the soft-wall dual model of QCD. We find
that hybrid and multiquark mesons are characterized by an increasingly large
CE. A similar behavior is observed for baryons, where the
CE of pentaquarks is larger than for three-quark baryons, for same radial
number. Configurational Entropy seems relevant in disentangling conventional
hadrons from exotica.Comment: 13 pages, 4 figure
decays in the standard model and in scenarios with universal extra dimensions
We study the radiative decays, which are
important to investigate CP violation, and are also relevant to assess the role
of the exclusive modes induced by the transition to saturate
the inclusive decay rate. Moreover, these channels do not
display the same hierarchy as modes, for which the
decay into is enhanced with respect to one into . The
three-body radiative decays reverse the role: we find that this experimentally
observed behavior (although affected by a large uncertainty in the case of the
) is reproduced in the theoretical analysis. We compute a form factor, needed for this study, using light cone QCD sum rules, and
discuss a relation expected to hold in the large energy limit for the light
meson. Finally, we examine in two extensions of the
standard model with universal extra dimensions, to investigate the sensitivity
of this rare mode to such a kind of new physics effects.Comment: RevTeX, 17 pages, 7 figures. High resolution figures available upon
request. Matches the published versio
QCD Interactions of Heavy Mesons with Pions by Light-Cone Sum Rules
Light-cone QCD sum rules are employed to compute the strong coupling
constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and
(B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ
doublets. The couplings are calculated both for finite values of the heavy
quark mass and in the infinite heavy quark mass limit, deriving sum rules for
m_Q \to \infty.Comment: Latex, 23 pages, 6 figures. Revised version to appear in Z. Phys.
On three-body decays and couplings of heavy mesons to light pseudoscalar mesons
We analyze the decay modes and and, using the available experimental data, we find bounds for the
constants g and h describing the strong coupling of heavy mesons to light
pseudoscalar mesons. Both the decay channels are dominated by broad L=1 charm
resonances; the dominance is effective also in and .Comment: LaTex, 16 pages, 5 figure
Radiative transitions of and
We study radiative decays of and using
light-cone QCD sum rules. In particular, we consider the decay modes
and and evaluate the hadronic parameters in the transition
amplitudes analyzing correlation functions of scalar, pseudoscalar, vector and
axial-vector quark currents. In the case of
we also consider determinations based on two different correlation functions in
HQET. The decay widths turn out to be different than previous estimates
obtained by other methods; the results favour the interpretation of
and as ordinary mesons.Comment: RevTex, 23 pages, 9 eps figure
The Riddle of Polarization in Transitions
Measurements of polarization fractions in transitions, with a
light vector meson, show that the longitudinal amplitude dominates in , , and decays and
not in the penguin induced decays , .
We study the effect of rescattering mediated by charmed resonances, finding
that in it can be responsible of the suppression of the
longitudinal amplitude. For the decay we find that the
longitudinal fraction cannot be too large without invoking new effects.Comment: LaTex, 14 pages, 3 figure
Holographic Oddballs
The spectrum of the glueball with is computed using different
bottom-up holographic models of QCD. The results indicate a lowest-lying state
lighter than in the determination by other methods, with mass
GeV. The in-medium properties of this gluonium are investigated, and stability
against thermal and density effects is compared to other hadronic systems.
Production and decay modes are identified, useful for searching the
glueball.Comment: 16 pages, 9 figures, 3 table
Identifying through its decay modes
We study how to assign the recently observed meson to an
appropriate level of the spectrum by the analysis of its decay modes
in final states comprising a light pseudoscalar meson. We use an effective
lagrangian approach with heavy quark and chiral symmetries, obtaining that the
measurement of the decay width would allow to distinguish between two
possible assignments.Comment: RevTex, 6 pages - references adde
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