3,060 research outputs found
Branching ratio and CP asymmetry of decays in the perturbative QCD approach
In this paper, we calculate the decay rate and CP asymmetry of the decay in perturbative QCD approach with Sudakov resummation. Since
none of the quarks in final states is the same as those of the initial
meson, this decay can occur only via annihilation diagrams in the standard
model. Besides the current-current operators, the contributions from the QCD
and electroweak penguin operators are also taken into account. We find that (a)
the branching ratio is about ; (b) the penguin diagrams
dominate the total contribution; and (c) the direct CP asymmetry is small in
size: no more than ; but the mixing-induced CP asymmetry can be as large
as ten percent testable in the near future LHC-b experiments.Comment: 12 pages, 4 figures included, RevTe
Branching ratios of decays in perturbative QCD approach
We study the rare decays , which can occur only via
annihilation type diagrams in the standard model. We calculate all of the four
modes, , in the framework of perturbative QCD approach
and give the branching ratios of the order about .Comment: 18 pages, 1 figure, Revte
Nonleptonic two-body charmless B decays involving a tensor meson in the Perturbative QCD Approach
Two-body charmless hadronic B decays involving a light tensor meson in the
final states are studied in the perturbative QCD approach based on
factorization. From our calculations, we find that the decay branching ratios
for color allowed tree-dominated decays and modes are of order and , respectively.
While other color suppressed tree-dominated decays have very small branching
ratios. In general, the branching ratios of most decays are in the range of
to , which are bigger by one or two orders of magnitude than
those predictions obtained in Isgur-Scora-Grinstein-Wise II model and in the
covariant light-front approach, but consistent with the recent experimental
measurements and the QCD factorization calculations. Since the decays with a
tensor meson emitted from vacuum are prohibited in naive factorization, the
contributions of nonfactorizable and annihilation diagrams are very important
to these decays, which are calculable in our perturbative QCD approach. We also
give predictions to the direct CP asymmetries, some of which are large enough
for the future experiments to measure. Because we considered the mixing between
and , the decay rates are enhanced significantly for some
decays involving meson, even with a small mixing angle.Comment: 26 pages, 2 figure
Study of pure annihilation type decays
In this work, we calculate the rare decays and in perturbative QCD approach with Sudakov resummation.
We give the branching ratio of for , which will
be tested soon in factories.
The decay has a very small branching ratio at
, due to the suppression from CKM matrix elements . It may be sensitive to new physics contributions.Comment: 14 pages, 1 figur
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