30,872 research outputs found
CP violation in supersymmetric theories
We review the present status of CP violating problem in supersymmetric
extensions of the standard model. We analyze the constraints imposed by the
experimental limits of the electron, neutron, and mercury electric dipole
moments on the supersymmetric CP phases and show that only the scenarios with
flavour-off- diagonal CP violation remain attractive. These scenarios require
hermitian Yukawa matrices which naturally arise in models with left-right
symmetry or a SU(3) flavour symmetry. In this case, epsilon_K and
epsilon'/epsilon can be saturated by a small non-universality of the soft
scalar masses through the gluino and chargino contributions respectively. The
model also predicts a strong correlation between A_{CP}(b-> s gamma) and the
neutron electric dipole moment. In this framework, the standard model gives a
the leading contribution to the CP asymmetry in B ->psi K_S decay, while the
dominant chargino contribution to this asymmetry is < 0.2. Thus, no constraint
is set on the non-universality of this model by the recent BaBar and Belle
measureets.Comment: 34 pages, 10 figures. Invited review article for International
Journal of Modern Physics
SU(5) Octet Scalar at the LHC
Color scalars are salient features of non-minimal SU(5) model, where Higgs
sector is extended by 45-dimensional multiplet. We show that gauge coupling
unification can be realized in this model with TeV octet scalar and
intermediate (~10^6 GeV) color-triplet scalar at scale larger than 10^{15} GeV.
We analyze the possible LHC signatures of these TeV octet scalars. We emphasize
that multi-(b)-jet final states provide significant signal for direct probe of
octet scalars at the LHC.Comment: 8 pages, 6 figure
A node-wise analysis of the uterine muscle networks for pregnancy monitoring
The recent past years have seen a noticeable increase of interest in the
correlation analysis of electrohysterographic (EHG) signals in the perspective
of improving the pregnancy monitoring. Here we propose a new approach based on
the functional connectivity between multichannel (4x4 matrix) EHG signals
recorded from the women abdomen. The proposed pipeline includes i) the
computation of the statistical couplings between the multichannel EHG signals,
ii) the characterization of the connectivity matrices, computed by using the
imaginary part of the coherence, based on the graph-theory analysis and iii)
the use of these measures for pregnancy monitoring. The method was evaluated on
a dataset of EHGs, in order to track the correlation between EHGs collected by
each electrode of the matrix (called node-wise analysis) and follow their
evolution along weeks before labor. Results showed that the strength of each
node significantly increases from pregnancy to labor. Electrodes located on the
median vertical axis of the uterus seemed to be the more discriminant. We
speculate that the network-based analysis can be a very promising tool to
improve pregnancy monitoring.Comment: 4 pages, 3 figures, accepted in the IEEE EMBC conferanc
Time Crystals from Minimum Time Uncertainty
Motivated by the Generalized Uncertainty Principle, covariance, and a minimum
measurable time, we propose a deformation of the Heisenberg algebra and show
that this leads to corrections to all quantum mechanical systems. We also
demonstrate that such a deformation implies a discrete spectrum for time. In
other words, time behaves like a crystal. As an application of our formalism,
we analyze the effect of such a deformation on the rate of spontaneous emission
in a hydrogen atom.Comment: 11 pages, to appear in Eur. Phys. J.
Phenomenological Aspects of TeV Scale Alternative Left-Right Model
We revisit the alternative left-right symmetric model, motivated by
superstring-inspired model. We systematically analyze the constraints
imposed by theoretical and experimental bounds on the parameter space of this
class of models. We perform a comprehensive analysis of the Higgs sector and
show that three neutral CP-even and two CP-odd Higgs bosons in addition to two
charged Higgs bosons can be light, of GeV.
We emphasise that our model has a potential to account for the recent Large
Hadron Collider results for signal strength of Higgs decays. We also explore
discovery signatures of the exotic down-type quark, which is one of the salient
predictions of this model.Comment: 21 pages, 8 figure
Fourth post-Newtonian effective-one-body Hamiltonians with generic spins
In a compact binary coalescence, the spins of the compact objects can have a significant effect on the orbital motion and gravitational-wave (GW) emission. For generic spin orientations, the orbital plane precesses, leading to characteristic modulations of the GW signal. The observation of precession effects is crucial to discriminate among different binary formation scenarios, and to carry out precise tests of General Relativity. Here, we work toward an improved description of spin effects in binary inspirals, within the effective-one-body (EOB) formalism, which is commonly used to build waveform models for LIGO and Virgo data analysis. We derive EOB Hamiltonians including the complete fourth post-Newtonian (4PN) conservative dynamics, which is the current state of the art. We place no restrictions on the spin orientations or magnitudes, or on the type of compact object (e.g., black hole or neutron star), and we produce the first generic-spin EOB Hamiltonians complete at 4PN order. We consider multiple spinning EOB Hamiltonians, which are more or less direct extensions of the varieties found in previous literature, and we suggest another simplified variant. Finally, we compare the circular-orbit, aligned-spin binding-energy functions derived from the EOB Hamiltonians to numerical-relativity simulations of the late inspiral. While finding that all proposed Hamiltonians perform reasonably well, we point out some interesting differences, which could guide the selection of a simpler, and thus faster-to-evolve EOB Hamiltonian to be used in future LIGO and Virgo inference studies
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