4,042 research outputs found
Supersymmetry Parameter Analysis with Fittino
We present the results of a realistic global fit of the Lagrangian parameters
of the Minimal Supersymmetric Standard Model to simulated data from ILC and LHC
with realistic estimates of the observable uncertainties. Higher order
radiative corrections are accounted for where ever possible to date. Results
are obtained for a modified SPS1a MSSM benchmark scenario but they were checked
not to depend critically on this assumption. Exploiting a simulated annealing
algorithm, a stable result is obtained without any a priori assumptions on the
fit parameters. Most of the Lagrangian parameters can be extracted at the
percent level or better if theoretical uncertainties are neglected. Neither LHC
nor ILC measurements alone will be sufficient to obtain a stable result. The
effects of theoretical uncertainties arising from unknown higher-order
corrections and parametric uncertainties are examined qualitatively. They
appear to be relevant and the result motivates further precision calculations.Comment: 6 pages, 2 figures, presented at the Linear Collider Workshop 2005,
Stanfor
Terrestrial and Solar Limits on Long-Lived Particles in a Dark Sector
Dark matter charged under a new gauge sector, as motivated by recent data,
suggests a rich GeV-scale "dark sector" weakly coupled to the Standard Model by
gauge kinetic mixing. The new gauge bosons can decay to Standard Model leptons,
but this mode is suppressed if decays into lighter dark sector particles are
kinematically allowed. These particles in turn typically have macroscopic decay
lifetimes that are constrained by two classes of experiments, which we discuss.
Lifetimes of 10 cm < c tau < 10^8 cm are constrained by existing terrestrial
beam-dump experiments. If, in addition, dark matter captured in the Sun (or
Earth) annihilates into these particles, lifetimes up to 10^15 cm are
constrained by solar observations. These bounds span fourteen orders of
magnitude in lifetime, but they are not exhaustive. Accordingly, we identify
promising new directions for experiments including searches for displaced
di-muons in B-factories, studies at high-energy and -intensity proton beam
dumps, precision gamma-ray and electronic measurements of the Sun, and
milli-charge searches re-analyzed in this new context.Comment: 9 pages, 9 figure
On the Origin of Light Dark Matter Species
TeV-mass dark matter charged under a new GeV-scale gauge force can explain
electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct
detection experiments are observing scattering of light stable states --
"GeV-Matter" -- that are charged under this force and constitute a small
fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark
sector are natural candidates for GeV-Matter that scatter off protons with a
universal cross-section of 5 x 10^{-38} cm^2 and can naturally be split by
10-30 keV so that their dominant interaction with protons is down-scattering.
As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously
explain the spectra observed by both CoGeNT and DAMA. The event rates in these
experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass
density. This abundance can arise directly from thermal freeze-out at weak
coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal
can be tested by searches for exotics in the BaBar and Belle datasets.Comment: 31 text pages, 4 figures, revision includes corrected Germanium
quenching factor and clarified text in Sec.
Immune-Mediated Inflammation May Contribute to the Pathogenesis of Cardiovascular Disease in Mucopolysaccharidosis Type I.
BackgroundCardiovascular disease, a progressive manifestation of α-L-iduronidase deficiency or mucopolysaccharidosis type I, continues in patients both untreated and treated with hematopoietic stem cell transplantation or intravenous enzyme replacement. Few studies have examined the effects of α-L-iduronidase deficiency and subsequent glycosaminoglycan storage upon arterial gene expression to understand the pathogenesis of cardiovascular disease.MethodsGene expression in carotid artery, ascending, and descending aortas from four non-tolerized, non-enzyme treated 19 month-old mucopolysaccharidosis type I dogs was compared with expression in corresponding vascular segments from three normal, age-matched dogs. Data were analyzed using R and whole genome network correlation analysis, a bias-free method of categorizing expression level and significance into discrete modules. Genes were further categorized based on module-trait relationships. Expression of clusterin, a protein implicated in other etiologies of cardiovascular disease, was assessed in canine and murine mucopolysaccharidosis type I aortas via Western blot and in situ immunohistochemistry.ResultsGene families with more than two-fold, significant increased expression involved lysosomal function, proteasome function, and immune regulation. Significantly downregulated genes were related to cellular adhesion, cytoskeletal elements, and calcium regulation. Clusterin gene overexpression (9-fold) and protein overexpression (1.3 to 1.62-fold) was confirmed and located specifically in arterial plaques of mucopolysaccharidosis-affected dogs and mice.ConclusionsOverexpression of lysosomal and proteasomal-related genes are expected responses to cellular stress induced by lysosomal storage in mucopolysaccharidosis type I. Upregulation of immunity-related genes implicates the potential involvement of glycosaminoglycan-induced inflammation in the pathogenesis of mucopolysaccharidosis-related arterial disease, for which clusterin represents a potential biomarker
Non-destructive measurement of the transition probability in a Sr optical lattice clock
We present the experimental demonstration of non-destructive probing of the
1S0-3P0 clock transition probability in an optical lattice clock with 87Sr
atoms. It is based on the phase shift induced by the atoms on a weak
off-resonant laser beam. The method we propose is a differential measurement of
this phase shift on two modulation sidebands with opposite detuning with
respect to the 1S0-1P1 transition, allowing a detection limited by the photon
shot noise. We have measured an atomic population of 10^4 atoms with a signal
to noise ratio of 100 per cycle, while keeping more than 95% of the atoms in
the optical lattice with a depth of 0.1 mK. The method proves simple and robust
enough to be operated as part of the whole clock setup. This detection scheme
enables us to reuse atoms for subsequent clock state interrogations,
dramatically reducing the loading time and thereby improving the clock
frequency stability.Comment: 4 pages, 5 figure
Differential dependencies of monocytes and neutrophils on dectin-1, dectin-2 and complement for the recognition of fungal particles in inflammation
Peer reviewedPublisher PD
A Comment on the Implementation of the Ziggurat Method
We show that the short period of the uniform random number generator in the published implementation of Marsaglia and Tsang's Ziggurat method for generating random deviates can lead to poor distributions. Changing the uniform random number generator used in its implementation fixes this issue.
Anxieties Disorder and Deviant Behaviors among Secondary School Studies in Obubra Local Government Area of Cross River State
This study was to determine the relationship between anxiety disorder and deviant behavior among senior secondary school students in Obubra Local Government Area of Cross River State. Various deviant behaviours of varying degrees ranging from truancy, lateness, fighting, bullying, cheating in examination, vandalism, drugs abuse, rape, disrespect to authority etc. leading to inadequate preparation towards academic test and examinations. Based on the above, hypothesis was formulated to guide the study. The study was delimited to Obubra Local Government Area and SS two students were used for the study. Anxiety disorder was delimited to phobic anxiety disorder. The instrument use was the Anxiety Disorder and Deviant Behavior Questionnaire (ADDBP) and it contained forty 40 items. A sample population of 247 students distributed among the five secondary schools in Obubra Local Government Area of Cross River State – Nigeria were used for the survey. Pearson product correlation coefficient was used to analyze the data. Based on the research findings recommendations were made
Complexes of Mercury(II) with p-Nitrosodimethylaniline and p-Nitrosodiethylaniline
Complexes of mercury(II) with p-nitrosodimethylaniline and
p-nitrosodiethylaniline have been prepared and characterized by
their spectral, magnetic and conductance measurements. Tetrahedral
coordination about the mercury(I1) ion has been proposed
for the halide complexes, while the nit rate complexes as sume an
octahedral geometry. The electronic spectra indicate a strong
ligand absorption with large molar absorptivitiy in both the solution
and solid states. The magnetic data reveal that the molecules
are asummetric, while infrared spectra show that the nitroso
moiety is coordinated to the metal
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