62,073 research outputs found
Consequences of R-Parity violating interactions for anomalies in and
We investigate the possibility of explaining the enhancement in semileptonic
decays of , the anomalies induced by in and violation of lepton
universality in
within the framework of R-parity violating (RPV) MSSM. Exchange of down type
right-handed squark coupled to quarks and leptons yield interactions which are
similar to leptoquark induced interactions that have been proposed to explain
the by tree level interactions and anomalies by loop induced interactions, simultaneously. However,
the Yukawa couplings in such theories have severe constraints from other rare
processes in and decays. Although this interaction can provide a viable
solution to anomaly, we show that with the severe constraint from
, it is impossible to solve the anomalies in process simultaneously.Comment: RevTex, 13 pages, three figures. In our earlier version, we had
neglected a contribution to C^{NP}_9 and obtained erroneous conclusions which
we have corrected them in this versio
Triple Neutral Gauge Boson Couplings in Noncommutative Standard Model
It has been shown recently that the triple neutral gauge boson couplings are
not uniquely determined in noncommutative extension of the Standard Model
(NCSM). Depending on specific schemes used, the couplings are different and may
even be zero. To distinguish different realizations of the NCSM, additional
information either from theoretical or experimental considerations is needed.
In this paper we show that these couplings can be uniquely determined from
considerations of unification of electroweak and strong interactions. Using
SU(5) as the underlying theory and integrating out the heavy degrees of
freedom, we obtain unique non-zero new triple , , , , , and couplings at the
leading order in the NCSM. We also briefly discuss experimental implications.Comment: 8 pages, Latex, no figur
Centers and Cocenters of -Hecke algebras
In this paper, we give explicit descriptions of the centers and cocenters of
-Hecke algebras associated to finite Coxeter groups.Comment: 13 pages, a mistake in 4.2 is correcte
A Study of Some Methods for Measuring CKM CP Violating Phases
We study the influence of penguin (especially, electroweak penguin) effects
on some methods of measuring the angles , , and in the
CKM unitarity triangle. We use next-to-leading order effective Hamiltonian, and
present numerical estimates based on the factorization approximation. We find
that some techniques suggested in the literature, especially for
determination, are not workable in light of the electroweak penguin effects.
Nevertheless, there are methods that would work for each angle determination.
For angle we consider mode and estimate the
penguin contamination. For angle we consider a method based on SU(3)
symmetry and carefully consider SU(3) breaking effects. We point out regions in
the parameter space where this method could be used reliably.Comment: 25 pages (Latex), 5 PS figs (uuencoded, epsf.tex
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
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