1,580 research outputs found
CP Violating Rate Difference Relations for and in Broken SU(3)
Within the standard model there exist certain relations between CP violating
rate differences in B decays in the SU(3) limit. We study SU(3) breaking
corrections to these relations in the case of charmless, hadronic, two body
decays using the improved factorization model of Ref.\cite{3}. We consider the
cases and for both and mesons. We present an
estimate for in terms of .Comment: Latex 13 pages, no figure
Determination of the magnetic susceptibility of the quark condensate using radiative heavy meson decays
We use a light-cone sum rule (LCSR) analysis of the branching ratios of
radiative meson decays to contrain the value of the magnetic susceptibility of
the quark condensate . For the first time, we use a complete set of
three-particle distribution amplitudes that enables us to give a consistent
prediction for the branching ratios. Furthermore we will make use of a very
recent update of several non-perturbative parameters. Our final result for
(assuming asymptotic wave
functions) agrees with the currently used value of .Comment: 21 pages, 4 figures, references adde
The Semileptonic Decays and from QCD Sum Rules
We investigate the semileptonic decays of B and D mesons into and
mesons, respectively, by means of QCD sum rules. We find that for the
vector formfactors involved the pole dominance hypothesis is valid to good
accuracy with pole masses in the expected range. Pole dominance, however, does
not apply to the axial formfactors which results in specific predictions for
the predominant polarization of the meson and the shape of the lepton
spectrum. For the total decay rates we find , , and .Comment: 23 pages, 12 figures included as uu-encoded file, needs REVTEX,
TUM--T31--39/9
Light-cone sum rules for form factors revisited
We reconsider and update the QCD light-cone sum rules for form
factors. The gluon radiative corrections to the twist-2 and twist-3 terms in
the correlation functions are calculated. The -quark mass is
employed, instead of the one-loop pole mass used in the previous analyses. The
light-cone sum rule for is fitted to the measured
-distribution in , fixing the input parameters with the
largest uncertainty: the Gegenbauer moments of the pion distribution amplitude.
For the vector form factor at zero momentum transfer we predict
. Combining it with the value of the
product extracted from experiment, we obtain
. In addition, the scalar
and penguin form factors and are
calculated.Comment: 33 pages, 7 figures, one figure and a few comments added, version to
appear in JHE
Next--to--Leading Order Corrections to Meson Masses in the Heavy Quark Effective Theory
We use the QCD sum rule approach to calculate the splitting between vector
and pseudoscalar mesons containing one light and one heavy quark, and the
kinetic energy of the heavy quark. Our result for the splitting induced by the
chromomagnetic interaction agrees to the experimental data on charm and beauty
mesons. For the matrix element of the kinetic energy operator, we obtain the
value .Comment: 33 ps., PS figures included, requires REVTEX.3 and psfig,
TUM-T31-42/93/R (additional contribution to kinetic energy taken into
account, marginal changes in the results
Column reduced rational matrix functions with given null-pole data in the complex plane
AbstractExplicit formulas are given for rational matrix functions which have a prescribed null-pole structure in the complex plane and are column reduced at infinity. A full parametrization of such functions is obtained. The results are specified and developed further for matrix polynomials
Analysis of the vertexes , and radiative decays ,
In this article, we study the vertexes and with the light-cone QCD sum rules, then assume the vector meson
dominance of the intermediate , and , and
calculate the radiative decays and .Comment: 28 pages, 4 tables, revised versio
Strong Couplings of Heavy Mesons to A Light Vector Meson in QCD
We make a detailed analysis of the and
strong couplings and
using QCD light cone sum rules(LCSR). The
existing some negligence is pointed out in the previous LCSR calculation on
) and an updated estimate is presented. Our
findings can be used to understand the behavior of the
semileptonic form factors at large momentum transitions.Comment: 15 pages, latex, 2 figures, version appearing in PRD, typos correcte
Analysis of the vertices and with light-cone QCD sum rules
In this article, we study the vertices and with the light-cone
QCD sum rules. The strong coupling constants and play an
important role in understanding the final-state re-scattering effects in the
hadronic B decays. They are related to the basic parameters and
respectively in the heavy quark effective Lagrangian, our numerical
values are smaller than the existing estimations.Comment: 16 pages, 6 figures, revised versio
Flavour SU(3) Symmetry in Charmless B Decays
QCD sum rules are used to estimate the flavour SU(3)-symmetry violation in
two-body B decays to pions and kaons. In the factorizable amplitudes the
SU(3)-violation manifests itself in the ratio of the decay constants f_K/f_pi
and in the differences between the B->K, B_s->K and B->pi form factors. These
effects are calculated from the QCD two-point and light-cone sum rules,
respectively, in terms of the strange quark mass and the ratio of the strange
and nonstrange quark-condensate densities. Importantly, QCD sum rules predict
that SU(3) breaking in the heavy-to-light form factors can be substantial and
does not vanish in the heavy-quark mass limit. Furthermore, we investigate the
strange-quark mass dependence of nonfactorizable effects in the B->K pi decay
amplitudes. Taking into account these effects we estimate the accuracy of
several SU(3)-symmetry relations between charmless B-decay amplitudes.Comment: Two references added, version to be published in Phys.Rev.D, 21
pages, 12 postscript figure
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