261 research outputs found
The Effects of Non-Local Interactions in Rare B Decays, B -> X_s l^+l^-
The effects of non-local interactions in rare B decays, \Bsll, are
investigated. We show the correlation between the branching ratio and the
forward-backward asymmetry via two coefficients of the non-local interactions.
This will certainly help us find any deviations from the standard model through
the non-local interactions.Comment: 16 pages, 5 figures, LaTeX, Accepted for IJMP
General analysis of time evolution of decay spectrum in B^0 -> pi^+ pi^- l^+ l^-
Using the general, model independent form of effective Hamiltonian, the decay
spectrum of B^0 -> pi^+ pi^- l^+ l^- decay is studied. The sensitivity of
experimentally measurable asymmetries to the new Wilson coefficients and time
is studied. It is observed that different asymmetries are sensitive to the new
Wilson coefficients and they can serve as an efficient tool for establishing
new physics beyond SM.Comment: 15 pp, 4 figures (postscript formatted), LaTex formatte
CP Asymmetry of in Low Invariant Mass Region
I analyzed the CP asymmetry of based on model-independent
analysis which includes twelve independent four Fermi operators. The CP
asymmetry is suppressed in the Standard Model, however, if some new physics
make it much larger, the present or the next generation B factories may catch
the CP violation in this decay mode. In this paper, we studied the correlation
of the asymmetry and the branching ratio, and then we will find only a type of
interactions can be enlarge the asymmetry. Therefore, in comparison with
experiments, we have possibility that we can constrain models beyond the
standard model.Comment: 12 pages, 5 figures, LaTeX, Accepted for Physical Review
Lepton polarization and CP-violating effects in "B -> K^* tau^+ tau^-" decay in standard and two Higgs doublet models
The most general model independent expressions for the CP-violating
asymmetry, longitudinal, transversal and normal polarizations of leptons are
derived. Application of these general results to the concrete models such as
Standard model and three different types of two Higgs doublet model is
discussed.Comment: 18 pages, 8 postscripted figure
New Physics Effects in Decays
We present a model-independent analysis of rare B decays, . The effect of possible new physics is written in terms of dimension-6
four-fermi interactions. The lepton number violating scalar- and tensor-type
interactions are included, and they induce decays. We show systematically how the branching ratios and
missing mass-squared spectrum depend on the coefficients of the four-fermi
interactions.Comment: 20 pages with 7 figure
Longitudinal polarization asymmetry of leptons in the pure leptonic B decays
Longitudinal lepton polarization asymmetry in B_q -> l l (q = d, s$ and l =
e, mu, tau) decays is investigated. The analysis is done in a general manner by
using the effective operators approach. It is shown that the longitudinal
lepton polarization asymmetry would provide a direct search for the scalar and
pseudoscalar type interactions, which are induced in all variants of
Higgs-doublet models.Comment: 7 page
Lepton Polarization and Forward-Backward Asymmetries in b -> s tau+ tau-
We study the spin polarizations of both tau leptons in the decay b -> s tau+
tau-. In addition to the polarization asymmetries involving a single tau, we
construct asymmetries for the case where both polarizations are simultaneously
measured. We also study forward-backward asymmetries with polarized tau's. We
find that a large number of asymmetries are predicted to be large, >~ 10%. This
permits the measurement of all Wilson coefficients and the b-quark mass, thus
allowing the standard model (SM) to be exhaustively tested. Furthermore, there
are many unique signals for the presence of new physics. For example,
asymmetries involving triple-product correlations are predicted to be tiny
within the SM, O(10^{-2}). Their observation would be a clear signal of new
physics.Comment: 21 pages, LaTeX, 4 figures (included). Paper somewhat reorganized,
references greatly expanded, conclusions unchange
Exclusive B -> K^* l^+ l^- decay with polarized K^* and new physics effects
Using the most general, model independent effective Hamiltonian, the
branching ratio of the (B -> K^* l^+ l^-) decay, when K^* meson is
longitudinally or transversally polarized, is presented. The dependence of the
branching ratio on the new Wilson coefficients, when K^* meson is polarized, is
studied. It is observed that the branching ratio is very sensitive to the
vector and tensor type interactions, which will be useful in search of new
physics beyond the Standard Model.Comment: 13 pp, 6 figures (postscript formatted), LaTex formatte
General analysis of lepton polarizations in rare B -> K^* l^+ l^- decay beyond the standard model
The general analysis of lepton polarization asymmetries in rare B -> K^* l^+
l^- decay is investigated. Using the most general, model independent effective
Hamiltonian, the general expressions of the longitudinal, normal and
transversal polarization asymmetries for l^- and l^+ and combinations of them
are presented. The dependence of lepton polarizations and their combinations on
new Wilson coefficients are studied in detail. Our analysis shows that the
lepton polarization asymmetries are very sensitive to the scalar and tensor
type interactions, which will be very useful in looking for new physics beyond
the standard model.Comment: 29 pp, 15 figure
New physics effects to the lepton polarizations in the B -> K l^+ l^- decay
Using the general, model independent form of the effective Hamiltonian, the
general expressions of the longitudinal, normal and transversal polarization
asymmetries for (l^-) and (l^+) and combinations of them for the exclusive (B
-> K l^+ l^-) decay are found. The sensitivity of lepton polarizations and
their combinations on new Wilson coefficients are studied. It is found that
there exist regions of Wilson coefficients for which the branching ratio
coincides with the Standard Model result while the lepton polarizations differ
substantially from the standard model prediction. Hence, studying lepton
polarization in these regions of new Wilson coefficients can serve as a
promising tool for establishing new physics beyond the Standard Model.Comment: 18 pp, 14 figures (postscript formatted), LaTex formatte
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