840 research outputs found
Footprints of Supersymmetry on Higgs Decay
Motivated by future collider proposals that aim to measure the Higgs
properties precisely, we study the partial decay widths of the lightest Higgs
boson in the minimal supersymmetric standard model with an emphasis on the
parameter region where all superparticles and heavy Higgs bosons are not
accessible at the LHC. Taking account of phenomenological constraints such as
the Higgs mass, flavor constraints, vacuum stability, and perturbativity of
coupling constants up to the grand unification scale, we discuss how large the
deviations of the partial decay widths from the standard model predictions can
be. These constraints exclude large fraction of the parameter region where the
Higgs widths show significant deviation from the standard model predictions.
Nevertheless, even if superparticles and the heavy Higgses are out of the reach
of 14TeV LHC, the deviation may be large enough to be observed at future
collider experiments.Comment: 24 pages, 8 figures, version accepted in JHE
Renormalization-Scale Uncertainty in the Decay Rate of False Vacuum
We study radiative corrections to the decay rate of false vacua, paying
particular attention to the renormalization-scale dependence of the decay rate.
The decay rate exponentially depends on the bounce action. The bounce action
itself is renormalization scale dependent. To make the decay rate
scale-independent, radiative corrections, which are due to the field
fluctuations around the bounce, have to be included. We show quantitatively
that the inclusion of the fluctuations suppresses the scale dependence, and
hence is important for the precise calculation of the decay rate. We also apply
our analysis to a supersymmetric model and show that the radiative corrections
are important for the Higgs-stau system with charge breaking minima.Comment: 15 pages, 2 figures; added reference
On the Gauge Invariance of the Decay Rate of False Vacuum
We study the gauge invariance of the decay rate of the false vacuum for the
model in which the scalar field responsible for the false vacuum decay has
gauge quantum number. In order to calculate the decay rate, one should
integrate out the field fluctuations around the classical path connecting the
false and true vacua (i.e., so-called bounce). Concentrating on the case where
the gauge symmetry is broken in the false vacuum, we show a systematic way to
perform such an integration and present a manifestly gauge-invariant formula of
the decay rate of the false vacuum.Comment: 17 pages, published versio
New Critical Point Induced by the Axial Anomaly in Dense QCD
We study the interplay between chiral and diquark condensates within the
framework of the Ginzburg-Landau free energy, and classify possible phase
structures of two and three-flavor massless QCD. The QCD axial anomaly acts as
an external field applied to the chiral condensate in a color superconductor
and leads to a crossover between the broken chiral symmetry and the color
superconducting phase, and, in particular, to a new critical point in the QCD
phase diagram.Comment: 4 pages, 4 figures included, version to appear in Phys. Rev. Let
Higgs mass and muon anomalous magnetic moment in the U(1) extended MSSM
We study phenomenological aspects of the MSSM with extra U(1) gauge symmetry.
We find that the lightest Higgs boson mass can be increased up to 125 GeV,
without introducing a large SUSY scale or large A-terms, in the frameworks of
the CMSSM and gauge mediated SUSY breaking (GMSB) models. This scenario can
simultaneously explain the discrepancy of the muon anomalous magnetic moment
(muon g-2) at the 1 sigma level, in both of the frameworks, U(1)-extended
CMSSM/GMSB models. In the CMSSM case, the dark matter abundance can also be
explained.Comment: 19 pages, 3 figures; submitted versio
Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario : Superpotential, Soft Terms and Sparticle Mass Spectrum
The physics of moduli fields is examined in the scenario where the gravitino
is relatively heavy with mass of order 10 TeV, which is favored in view of the
severe gravitino problem. The form of the moduli superpotential is shown to be
determined, if one imposes a phenomenological requirement that no physical CP
phase arise in gaugino masses from conformal anomaly mediation. This bottom-up
approach allows only two types of superpotential, each of which can have its
origins in a fundamental underlying theory such as superstring. One
superpotential is the sum of an exponential and a constant, which is identical
to that obtained by Kachru et al (KKLT), and the other is the racetrack
superpotential with two exponentials. The general form of soft supersymmetry
breaking masses is derived, and the pattern of the superparticle mass spectrum
in the minimal supersymmetric standard model is discussed with the KKLT-type
superpotential. It is shown that the moduli mediation and the anomaly mediation
make comparable contributions to the soft masses. At the weak scale, the
gaugino masses are rather degenerate compared to the minimal supergravity,
which bring characteristic features on the superparticle masses. In particular,
the lightest neutralino, which often constitutes the lightest superparticle and
thus a dark matter candidate, is a considerable admixture of gauginos and
higgsinos. We also find a small mass hierarchy among the moduli, gravitino, and
superpartners of the standard-model fields. Cosmological implications of the
scenario are briefly described.Comment: 45 pages, 10 figures, typos correcte
Lepton Flavor Violation and Cosmological Constraints on R-parity Violation
In supersymmetric standard models R-parity violating couplings are severely
constrained, since otherwise they would erase the existing baryon asymmetry
before the electroweak transition. It is often claimed that this cosmological
constraint can be circumvented if the baryon number and one of the lepton
flavor numbers are sufficiently conserved in these R-parity violating
couplings, because B/3-L_i for each lepton flavor is separately conserved by
the sphaleron process. We discuss the effect of lepton flavor violation on the
B-L conservation, and show that even tiny slepton mixing angles \theta_{12}
\gsim {\cal O}(10^{-4}) and \theta_{23}, \theta_{13}\gsim {\cal O}(10^{-5})
will spoil the separate B/3-L_i conservation. In particular, if lepton flavor
violations are observed in experiments such as MEG and B-factories, it will
imply that all the R-parity violating couplings must be suppressed to avoid the
B-L erasure. We also discuss the implication for the decay of the lightest MSSM
particle at the LHC.Comment: 21 pages, 7 figures. v2: minor change
AgriSORT: A Simple Online Real-time Tracking-by-Detection framework for robotics in precision agriculture
The problem of multi-object tracking (MOT) consists in detecting and tracking
all the objects in a video sequence while keeping a unique identifier for each
object. It is a challenging and fundamental problem for robotics. In precision
agriculture the challenge of achieving a satisfactory solution is amplified by
extreme camera motion, sudden illumination changes, and strong occlusions. Most
modern trackers rely on the appearance of objects rather than motion for
association, which can be ineffective when most targets are static objects with
the same appearance, as in the agricultural case. To this end, on the trail of
SORT [5], we propose AgriSORT, a simple, online, real-time
tracking-by-detection pipeline for precision agriculture based only on motion
information that allows for accurate and fast propagation of tracks between
frames. The main focuses of AgriSORT are efficiency, flexibility, minimal
dependencies, and ease of deployment on robotic platforms. We test the proposed
pipeline on a novel MOT benchmark specifically tailored for the agricultural
context, based on video sequences taken in a table grape vineyard, particularly
challenging due to strong self-similarity and density of the instances. Both
the code and the dataset are available for future comparisons.Comment: 8 pages, 5 figures, submitted to International Conference on Robotics
and Automation (ICRA) 2024. Code and dataset will be soon available on my
github. This work has been submitted to the IEEE for possible publication.
Copyright may be transferred without notice, after which this version may no
longer be accessibl
Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa
We have constructed a pressuretemperature () phase diagram of
-induced superconductivity in EuFeAs single crystals, via
resistivity () measurements up to 3.2 GPa. As hydrostatic pressure is
applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at
shifts to lower temperatures, and the corresponding resistive
anomaly becomes undetectable for 2.5 GPa. This suggests that the
critical pressure where becomes zero is about 2.5
GPa. We have found that the AF order of the Eu moments survives up to
3.2 GPa without significant changes in the AF ordering temperature
. The superconducting (SC) ground state with a sharp transition
to zero resistivity at 30 K, indicative of bulk
superconductivity, emerges in a pressure range from 2.5
GPa to 3.0 GPa. At pressures close to but outside the SC phase, the
curve shows a partial SC transition (i.e., zero resistivity is not
attained) followed by a reentrant-like hump at approximately
with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like
strain component is applied using a solid pressure medium, the partial
superconductivity is continuously observed in a wide pressure range from 1.1
GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B,
selected as "Editors' Suggestion
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