161 research outputs found
New-Physics Effects on Triple-Product Correlations in Lambda_b Decays
We adopt an effective-lagrangian approach to compute the new-physics
contributions to T-violating triple-product correlations in charmless Lambda_b
decays. We use factorization and work to leading order in the heavy-quark
expansion. We find that the standard-model (SM) predictions for such
correlations can be significantly modified. For example, triple products which
are expected to vanish in the SM can be enormous (~50%) in the presence of new
physics. By measuring triple products in a variety of Lambda_b decays, one can
diagnose which new-physics operators are or are not present. Our general
results can be applied to any specific model of new physics by simply
calculating which operators appear in that model.Comment: 20 pages, LaTeX, no figures. Added a paragraph (+ references)
discussing nonfactorizable effects. Conclusions unchange
A theory of normed simulations
In existing simulation proof techniques, a single step in a lower-level
specification may be simulated by an extended execution fragment in a
higher-level one. As a result, it is cumbersome to mechanize these techniques
using general purpose theorem provers. Moreover, it is undecidable whether a
given relation is a simulation, even if tautology checking is decidable for the
underlying specification logic. This paper introduces various types of normed
simulations. In a normed simulation, each step in a lower-level specification
can be simulated by at most one step in the higher-level one, for any related
pair of states. In earlier work we demonstrated that normed simulations are
quite useful as a vehicle for the formalization of refinement proofs via
theorem provers. Here we show that normed simulations also have pleasant
theoretical properties: (1) under some reasonable assumptions, it is decidable
whether a given relation is a normed forward simulation, provided tautology
checking is decidable for the underlying logic; (2) at the semantic level,
normed forward and backward simulations together form a complete proof method
for establishing behavior inclusion, provided that the higher-level
specification has finite invisible nondeterminism.Comment: 31 pages, 10figure
R-parity-violating SUSY and CP violation in B --> phi K_s
Recent measurements of CP asymmetry in B --> phi K_S appear to be
inconsistent with Standard Model expectations. We explore the effect of
R-parity-violating SUSY to understand the data.Comment: Equations corrected. Conclusions unchanged. Latex, 6 pages, one fi
Triple-Product Correlations in B -> V1 V2$ Decays and New Physics
In this paper we examine T-violating triple-product correlations (TP's) in B
-> V1 V2 decays. TP's are excellent probes of physics beyond the standard model
(SM) for two reasons: (i) within the SM, most TP's are expected to be tiny, and
(ii) unlike direct CP asymmetries, TP's are not suppressed by the small strong
phases which are expected in B decays. TP's are obtained via the angular
analysis of B -> V1 V2. In a general analysis based on factorization, we
demonstrate that the most promising decays for measuring TP's in the SM involve
excited final-state vector mesons, and we provide estimates of such TP's. We
find that there are only a handful of decays in which large TP's are possible,
and the size of these TP's depends strongly on the size of nonfactorizable
effects. We show that TP's which vanish in the SM can be very large in models
with new physics. The measurement of a nonzero TP asymmetry in a decay where
none is expected would specifically point to new physics involving large
couplings to the right-handed b-quark.Comment: 42 pages, LaTeX, no figures. Title changed, several explanatory
paragraphs added, references added, analysis and conclusions unchange
A new CP violating observable for the LHC
We study a new type of CP violating observable that arises in three body
decays that are dominated by an intermediate resonance. If two interfering
diagrams exist with different orderings of final state particles, the required
CP-even phase arises due to the different virtualities of the resonance in each
of the two diagrams. This method can be an important tool for accessing new CP
phases at the LHC and future colliders.Comment: 22 pages, v2: discussion of charged particle decays and a few
references added v3: typos corrected, matches published versio
Polya's inequalities, global uniform integrability and the size of plurisubharmonic lemniscates
First we prove a new inequality comparing uniformly the relative volume of a
Borel subset with respect to any given complex euclidean ball \B \sub \C^n
with its relative logarithmic capacity in \C^n with respect to the same ball
\B.
An analoguous comparison inequality for Borel subsets of euclidean balls of
any generic real subspace of \C^n is also proved.
Then we give several interesting applications of these inequalities.
First we obtain sharp uniform estimates on the relative size of \psh
lemniscates associated to the Lelong class of \psh functions of logarithmic
singularities at infinity on \C^n as well as the Cegrell class of
\psh functions of bounded Monge-Amp\`ere mass on a hyperconvex domain \W
\Sub \C^n.
Then we also deduce new results on the global behaviour of both the Lelong
class and the Cegrell class of \psh functions.Comment: 25 page
Analysis of Various Polarization Asymmetries In The Inclusive Decay In The Fourth-Generation Standard Model
In this study a systematical analysis of various polarization asymmetries in
inclusive b \rar s \ell^+ \ell^- decay in the standard model (SM) with four
generation of quarks is carried out. We found that the various asymmetries are
sensitive to the new mixing and quark masses for both of the and
channels. Sizeable deviations from the SM values are obtained. Hence, b \rar s
\ell^+ \ell^- decay is a valuable tool for searching physics beyond the SM,
especially in the indirect searches for the fourth-generation of quarks (.Comment: 19 Pages, 10 Figures, 3 Table
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