3,847 research outputs found
A method for determining CP violating phase
A new way of determining the phases of weak amplitudes in charged decays
based on SU(3) symmetry is proposed. The CP violating phase can now be
determined without the previous difficulty associated with electroweak
penguins.Comment: 9 pages plus one figure, Revte
The CP violating phase from global fit of rare charmless hadronic B decays
We study constraints on the CP violating phase in the
Kobayashi-Maskawa model using available experimental data. We first follow the
conventional method to up date the constraint on by performing a
analysis using data from , and
. We also include the recent information on in
the analysis. We obtain the best fit for to be and the 95%
C.L. allowed range to be . We then develop a method to
carry out a analysis based on SU(3) symmetry using data from and . We also discuss SU(3) breaking effects from model
estimate. We find that present data on can also give some
constraint on although weaker than the earlier method limited by the
present experimental errors. Future improved data will provide more stringent
constraint. Finally we perform a combined fit using data from ,
, , and rare charmless
hadronic B decays. The combined analysis gives for the best
fit value and as the 95% C.L. allowed range. Several
comments on other methods to determine based on SU(3) symmetry are
also provided.Comment: Revised verion with the new experimental data from Belle and Babar
included in the analysis to obtain the global fit for the CP violating phase
gamma. RevTex, 32 pages and 8 figure
Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays
We study effects of new physics beyond the Standard Model on SU(3) symmetry
in charmless hadronic two body B decays. It is found that several equalities
for some of the decay amplitudes, such as , , , predicted by SU(3) symmetry in the SM are not affected by new
physics. These relations provide important electroweak model independent tests
for SU(3) symmetry in B decays.Comment: 4 pages, revte
in the Standard Model
In this paper we investigate the possibility of studying form
factor using the semi-inclusive decays . In general
semi-inclusive decays involve several hadronic parameters. But for
decays we find that in the factorization
approximation, the only unknown hadronic parameters are the form factors
. Therefore these form factors can be studied in decays. Using theoretical model calculations for the form
factors the branching ratios for and
, with the cut GeV, are
estimated to be in the ranges of and ,
respectively, depending on the value of . The combined branching ratio
for is about and is insensitive to . We also discuss CP
asymmetries in these decay modes.Comment: RevTex 8 pages and two figure
Constraints on the phase and new physics from Decays
Recent results from CLEO on indicate that the phase may
be substantially different from that obtained from other fit to the KM matrix
elements in the Standard Model. We show that extracted using is sensitive to new physics occurring at loop level. It provides
a powerful method to probe new physics in electroweak penguin interactions.
Using effects due to anomalous gauge couplings as an example, we show that
within the allowed ranges for these couplings information about
obtained from can be very different from the Standard
Model prediction.Comment: Revised version with analysis done using new data from CLEO. RevTex,
11 Pages with two figure
Two-body Cabibbo-suppressed Decays of Charmed Baryons into Vector Mesons and into Photons
The heavy quark effective theory and the factorization approximation are used
to treat the Cabibbo-suppressed decays of charmed baryons to vector mesons,
,
and . The input from two recent experimental results on
decays allows the estimation of the branching ratios for these modes, which
turn out to be between and . The long distance contribution
of these transitions via vector meson dominance to the radiative weak processes
, and
leads to quite small branching ratios,
; the larger value holds if a sum rule between the coupling
constants of the vector mesons is broken.Comment: 11 pages, latex, no figure
CP Violation in a Multi-Higgs Doublet Model
We study CP violation in a multi-Higgs doublet model based on a horizontal symmetry. We consider two mechanisms for CP violation in this
model: a) CP violation due to complex Yukawa couplings; and b) CP violation due
to scalar-pseudoscalar mixings. We find that the predictions for
, CP violation in B decays and the electric dipole moments
of neutron and electron are different between these two mechanisms. These
predictions are also dramatically different from the minimal Standard Model
predictions.Comment: 17 pages + one figure, Revtex. Talk presented by Deshpande at the
Conference WHEPP-3, December 199
Semi-Inclusive B\to K(K^*) X Decays with Initial Bound State Effects
The effects of initial quark bound state for the semi-inclusive decays
are studied using light cone expansion and heavy quark
effective theory methods. We find that the initial bound state effects on the
branching ratios and CP asymmetries are small. In the light cone expansion
approach, the CP-averaged branching ratios are increased by about 2% with
respect to the free -quark decay. For , the
CP-averaged branching ratios are sensitive to the phase and the CP
asymmetry can be as large as 7% (14%), whereas for the CP-averaged branching ratios are not sensitive to and
the CP asymmetries are small (). The CP-averaged branching ratios are
predicted to be in the ranges [] for and [] for , depending on the value of the CP violating phase . In
the heavy quark effective theory approach, we find that the branching ratios
are decreased by about 10% and the CP asymmetries are not affected. These
predictions can be tested in the near future.Comment: 29 pages, 12 ps figure
One-loop flavor changing electromagnetic transitions
We discuss the effect of the external fermion masses in the flavor-changing
radiative transitions of a heavy fermion (quark or lepton) to a lighter fermion
at the one-loop level, and point out an often overlooked crucial difference in
the sign of a charge factor between transitions of the down type
and the up type . We give formulas for the
effective vertex in various approximations and the exact formula for and .Comment: LaTeX 16 pages + 4 postscript figures. Misprints corrected, some
Comments adde
SUSY GUTs contributions and model independent extractions of CP phases
We consider the origin of new phases in supersymmetric grand unification
model, and show how significant new contributions arise from the gluino
mediated diagram. We then present a more general model independent analysis of
various modes of B-decays suggested previously for measurement of the CKM
phases and point out what they really measure. It is in principle possible to
separate out all the phases.Comment: 13 pages (Latex), 2 PS figures, a few remarks are added and a typo is
corrected. To appear in Phys. Rev. Let
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