194 research outputs found
On the Reliability Function of Distributed Hypothesis Testing Under Optimal Detection
The distributed hypothesis testing problem with full side-information is
studied. The trade-off (reliability function) between the two types of error
exponents under limited rate is studied in the following way. First, the
problem is reduced to the problem of determining the reliability function of
channel codes designed for detection (in analogy to a similar result which
connects the reliability function of distributed lossless compression and
ordinary channel codes). Second, a single-letter random-coding bound based on a
hierarchical ensemble, as well as a single-letter expurgated bound, are derived
for the reliability of channel-detection codes. Both bounds are derived for a
system which employs the optimal detection rule. We conjecture that the
resulting random-coding bound is ensemble-tight, and consequently optimal
within the class of quantization-and-binning schemes
Future prospects of B physics
In recent years, the CKM picture of flavor and CP violation has been
confirmed, mainly due to B decay data. Yet, it is likely that there are small
corrections to this picture. We expect to find new physics not much above the
weak scale. This new physics could modify flavor changing processes compared to
their SM expectations. Much larger B decay data sets, which are expected from
LHCb and super--factories, will be used to search for these deviations with
much improved sensitivity. The combination of low and high energy data will be
particularly useful to probe the structure of new physics.Comment: 19 pages. To appear in the Progress of Theoretical Physics special
issue commemorating Kobayashi and Maskawa Nobel prize. v2: references added.
Final version to appear in the journa
CP Violation Beyond the Standard Model
We review CP violation in various extensions of the electroweak sector of the
Standard Model. A particular emphasis is put on supersymmetric models. We
describe the two CP problems of supersymmetry, concerning and
. We critically review the various mechanisms that have been
suggested to solve these problems: exact universality, approximate CP symmetry,
alignment, approximate universality and heavy squarks. We explain how future
measurements of CP violation will test these mechanisms. We describe extensions
of the quark sector and their implications on CP asymmetries in neutral B
decays, on the decay and on . We
discuss CP violation in charged scalar exchange in models with natural flavor
conservation and explain how transverse lepton polarization in meson decays can
probe such models. CP violation in neutral scalar exchange arises in models of
horizontal symmetries and may be manifest in heavy quark (b and t) physics. We
describe the implications of Left-Right Symmetric models on ,
, and CP asymmetries in B decays. Finally, we
briefly discuss the potential of future measurements of CP violation to
discover New Physics.Comment: 50 pages, harvmac, 1 figure. To appear in the Review Volume "Heavy
Flavours II", eds. A.J. Buras and M. Lindner, Advanced Series on Directions
in High Energy Physics, World Scientific Publishing Co., Singapor
Isotropy in Group Cohomology
The analogue of Lagrangians for symplectic forms over finite groups is
studied, motivated by the fact that symplectic G-forms with a normal Lagrangian
N<G are in one-to-one correspondence, up to inflation, with bijective 1-cocycle
data on the quotients G/N. This yields a method to construct groups of central
type from such quotients, known as Involutive Yang-Baxter groups. Another
motivation for the search of normal Lagrangians comes from a non-commutative
generalization of Heisenberg liftings which require normality.
Although it is true that symplectic forms over finite nilpotent groups always
admit Lagrangians, we exhibit an example where none of these subgroups is
normal. However, we prove that symplectic forms over nilpotent groups always
admit normal Lagrangians if all their p-Sylow subgroups are of order less than
p^8
and leptonic decays as probes of solutions to the puzzle
Experimental measurements of the ratios () show a
deviation from the Standard Model prediction. In the absence of
light right-handed neutrinos, a new physics contribution to
decays necessarily modifies also and/or transitions. These contributions lead to violation of lepton
flavor universality in, respectively, and leptonic decays. We
analyze the constraints resulting from measurements of the leptonic
vector-meson decays on solutions to the puzzle. Available data
from BaBar and Belle can already disfavor some of the new physics explanations
of this anomaly. Further discrimination can be made by measuring
in the upcoming Belle II experiment.Comment: Version published in JHEP, 17 pages, 7 figure
A quantitative study of leukocyte infiltration in the gut lamina propria of gnotobiotic and salmonella mono-contaminated pigs
Department: Surgery & Medicine
The importance of N2 leptogenesis
We argue that fast interactions of the lightest singlet neutrino would
project part of a preexisting lepton asymmetry onto a direction that is
protected from washout effects, thus preventing it from being erased. In
particular, we consider an asymmetry generated in decays, assuming that
interactions are fast enough to bring into full thermal
equilibrium. If decays occur at T\gsim 10^9 GeV, that is, before the
muon Yukawa interactions enter into thermal equilibrium, then generically part
of survives. In this case some of the constraints implied by the standard
leptogenesis scenario hold only if . For T\lsim 10^9
GeV, is generally erased, unless special alignment/orthogonality
conditions in flavor space are realized.Comment: 5 pages. A few clarifications added, conclusions unchanged. Version
published in Phys. Rev. Lett. (Title changed in journal
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