128,988 research outputs found
Light Front Approach for Strong and Weak Decays of Pentaquarks
Strong and weak decays of pentaquarks are studied in the framework of the
light-front approach.Comment: 3 pages, talk given at the 2004 DPF Meeting, Riverside, CA. Aug
26-31, 200
Phenomenological Applications of QCD Factorization to Semi-inclusive B Decays
We have systematically investigated the semi-inclusive B decays ,
which are manifestations of the quark decay , within a framework
inspired by QCD-improved factorization. These decays are theoretically clean
and have distinctive experimental signatures. We focus on a class of these that
do not require any form factor information and therefore may be especially
suitable for extracting information on the angles and of the
unitarity triangle. The strong phase coming from final-state rescattering due
to hard gluon exchange between the final states can induce large rate
asymmetries for tree-dominated color-suppressed modes
. The nonfactorizable hard spectator
interactions in the 3-body decay , though phase-space
suppressed, are extremely important for the tree-dominated modes
, and the
penguin-dominated mode . Our result for is in agreement with experiment. , , and are the most promising ones in searching for direct CP
violation: they have branching ratios of order and CP rate
asymmetries of order .Comment: 12 pages, talk given at International Conference on Flavor Physics,
Zhang-Jia-Jie City, Hunan, China, 31 May - 6 June, 200
Hadronic Two-Body Charmless B Decays
Implications of recent CLEO measurements of hadronic charmless B decays are
discussed.Comment: 7 pages, invited talk presented at the Third International Conference
on B Physics and CP Violation, Dec. 3-7, Taipe
SU(3) symmetry breaking and CP violation in D -> PP decays
Evidence of CP violation in the charm sector has been observed recently by
the LHCb and CDF Collaborations. Adopting the topological diagram approach, we
study flavor SU(3) symmetry breaking effects in the weak decay tree amplitudes
of singly Cabibbo-suppressed decays. The symmetry breaking in the
color-allowed and color-suppressed amplitudes is estimated with the help of the
factorization ansatz, while that in the -exchange amplitude is done by
fitting to related branching fraction data. We find that the -exchange
amplitudes stay in the second quadrant relative to the color-allowed tree
amplitude, albeit there are two possibilities for one type of -exchange
amplitude. The weak decay penguin amplitudes, on the other hand, are evaluated
within the framework of QCD factorization. Using the input of topological tree
amplitudes extracted from the Cabibbo-favored decay modes and the perturbative
results for QCD penguin amplitudes, we make predictions for the branching
fractions and CP asymmetries of singly Cabibbo-suppressed modes. The
predictions of branching fractions are generally improved from those in the
SU(3) limit. We conclude that the direct CP asymmetry difference between and is about and
for the two solutions of -exchange amplitudes,
respectively. We also find that the CP asymmetry of D^0\to K^0\ov K^0
dominated by the interference between -exchange amplitudes ranges from
to . We study phenomenological
implications of two new physics scenarios for explaining the observed CP
asymmetry in the charm sector, one with large penguin amplitudes and the other
with a large chromomagnetic dipole operator. We find that the two scenarios can
be discriminated by the measurements of CP asymmetries of a set of decay modes.Comment: 23 pages, three new paragraphs added in the beginning of Sec. III.
Version to appear in PRD. arXiv admin note: substantial text overlap with
arXiv:1201.078
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