749 research outputs found
Neutrino Fluxes from CMSSM LSP Annihilations in the Sun
We evaluate the neutrino fluxes to be expected from neutralino LSP
annihilations inside the Sun, within the minimal supersymmetric extension of
the Standard Model with supersymmetry-breaking scalar and gaugino masses
constrained to be universal at the GUT scale (the CMSSM). We find that there
are large regions of typical CMSSM planes where the LSP
density inside the Sun is not in equilibrium, so that the annihilation rate may
be far below the capture rate. We show that neutrino fluxes are dependent on
the solar model at the 20% level, and adopt the AGSS09 model of Serenelli et
al. for our detailed studies. We find that there are large regions of the CMSSM
planes where the capture rate is not dominated by
spin-dependent LSP-proton scattering, e.g., at large along the CMSSM
coannihilation strip. We calculate neutrino fluxes above various threshold
energies for points along the coannihilation/rapid-annihilation and focus-point
strips where the CMSSM yields the correct cosmological relic density for
tan(beta) = 10 and 55 for > 0, exploring their sensitivities to
uncertainties in the spin-dependent and -independent scattering matrix
elements. We also present detailed neutrino spectra for four benchmark models
that illustrate generic possibilities within the CMSSM. Scanning the
cosmologically-favored parts of the parameter space of the CMSSM, we find that
the IceCube/DeepCore detector can probe at best only parts of this parameter
space, notably the focus-point region and possibly also at the low-mass tip of
the coannihilation strip.Comment: 32 pages, 13 figures. v2: updated/expanded discussion of
IceCube/DeepCor
Neutrino Fluxes from NUHM LSP Annihilations in the Sun
We extend our previous studies of the neutrino fluxes expected from
neutralino LSP annihilations inside the Sun to include variants of the minimal
supersymmetric extension of the Standard Model (MSSM) with squark, slepton and
gaugino masses constrained to be universal at the GUT scale, but allowing one
or two non-universal supersymmetry-breaking parameters contributing to the
Higgs masses (NUHM1,2). As in the constrained MSSM (CMSSM) with universal Higgs
masses, there are large regions of the NUHM parameter space where the LSP
density inside the Sun is not in equilibrium, so that the annihilation rate may
be far below the capture rate, and there are also large regions where the
capture rate is not dominated by spin-dependent LSP-proton scattering. The
spectra possible in the NUHM are qualitatively similar to those in the CMSSM.
We calculate neutrino-induced muon fluxes above a threshold energy of 10 GeV,
appropriate for the IceCube/DeepCore detector, for points where the NUHM yields
the correct cosmological relic density for representative choices of the NUHM
parameters. We find that the IceCube/DeepCore detector can probe regions of the
NUHM parameter space in addition to analogues of the focus-point strip and the
tip of the coannihilation strip familiar from the CMSSM. These include regions
with enhanced Higgsino-gaugino mixing in the LSP composition, that occurs where
neutralino mass eigenstates cross over. On the other hand, rapid-annihilation
funnel regions in general yield neutrino fluxes that are unobservably small.Comment: 23 pages, 11 figures. v2: expanded threshold discussion, small
changes to match PRD versio
Investigation of nasal colonization of health care workers by methicillin-resistant Staphylococcus aureus with using new generation real-time PCR assay: Discussing of risks
Methicillin-resistant Staphylococcus aureus (MRSA) is a nasal infectious pathogen which is becoming of significant importance year by year. Mortality, morbidity and treatment costs of MRSA infectionshave all increased. The most effective preventative tool is rapid confirmation of MRSA existence, followed by efficient execution of the required infection control measures. This study was performedwith the aim of evaluating MRSA colonization in health care staff from intensive care units (internal and surgical intensive care units) (ICUs) and how certain risk factors affect their colonization status. The study was conducted prospectively using samples obtained from nasal swabs of health-care staffs working in different missions in the intensive care unit of Gaziantep University Training Hospital in southeast of Turkey. The nasal swab samples were processed using a real-time PCR method platformcalled GeneXpert (Cepheid). Our PCR screen revealed the presence of MRSA in 14 of 98 health-care staffs. Of these 14 health-care staffs carrying nasal MRSA, 10 were male, 8 were assistant health-care personnel and 11 have been working for over one year in the intensive care unit. Our data showed that male gender and an employment during of more than one year served as significant risk factors for nasal MRSA colonization
Dark Matter in SuperGUT Unification Models
After a brief update on the prospects for dark matter in the constrained
version of the MSSM (CMSSM) and its differences with models based on minimal
supergravity (mSUGRA), I will consider the effects of unifying the
supersymmetry-breaking parameters at a scale above M_{GUT}. One of the
consequences of superGUT unification, is the ability to take vanishing scalar
masses at the unification scale with a neutralino LSP dark matter candidate.
This allows one to resurrect no-scale supergravity as a viable phenomenological
model.Comment: 12 pages, 16 figures, To be published in the Proceedings of the 6th
DSU Conference, Leon, Mexico, ed. D. Delepin
Galactic-Centre Gamma Rays in CMSSM Dark Matter Scenarios
We study the production of gamma rays via LSP annihilations in the core of
the Galaxy as a possible experimental signature of the constrained minimal
supersymmetric extension of the Standard Model (CMSSM), in which
supersymmetry-breaking parameters are assumed to be universal at the GUT scale,
assuming also that the LSP is the lightest neutralino chi. The part of the
CMSSM parameter space that is compatible with the measured astrophysical
density of cold dark matter is known to include a stau_1 - chi coannihilation
strip, a focus-point strip where chi has an enhanced Higgsino component, and a
funnel at large tanb where the annihilation rate is enhanced by the poles of
nearby heavy MSSM Higgs bosons, A/H. We calculate the total annihilation rates,
the fractions of annihilations into different Standard Model final states and
the resulting fluxes of gamma rays for CMSSM scenarios along these strips. We
observe that typical annihilation rates are much smaller in the coannihilation
strip for tanb = 10 than along the focus-point strip or for tanb = 55, and that
the annihilation branching ratios differ greatly between the different dark
matter strips. Whereas the current Fermi-LAT data are not sensitive to any of
the CMSSM scenarios studied, and the calculated gamma-ray fluxes are probably
unobservably low along the coannihilation strip for tanb = 10, we find that
substantial portions of the focus-point strips and rapid-annihilation funnel
regions could be pressured by several more years of Fermi-LAT data, if
understanding of the astrophysical background and/or systematic uncertainties
can be improved in parallel.Comment: 33 pages, 12 figures, comments and references added, version to
appear in JCA
A Prediction Model to Prioritize Individuals for a SARS-CoV-2 Test Built from National Symptom Surveys
Background: The gold standard for COVID-19 diagnosis is detection of viral RNA through PCR. Due to global limitations in testing capacity, effective prioritization of individuals for testing is essential. Methods: We devised a model estimating the probability of an individual to test positive for COVID-19 based on answers to 9 simple questions that have been associated with SARS-CoV-2 infection. Our model was devised from a subsample of a national symptom survey that was answered over 2 million times in Israel in its first 2 months and a targeted survey distributed to all residents of several cities in Israel. Overall, 43,752 adults were included, from which 498 self-reported as being COVID-19 positive. Findings: Our model was validated on a held-out set of individuals from Israel where it achieved an auROC of 0.737 (CI: 0.712–0.759) and auPR of 0.144 (CI: 0.119–0.177) and demonstrated its applicability outside of Israel in an independently collected symptom survey dataset from the US, UK, and Sweden. Our analyses revealed interactions between several symptoms and age, suggesting variation in the clinical manifestation of the disease in different age groups. Conclusions: Our tool can be used online and without exposure to suspected patients, thus suggesting worldwide utility in combating COVID-19 by better directing the limited testing resources through prioritization of individuals for testing, thereby increasing the rate at which positive individuals can be identified. Moreover, individuals at high risk for a positive test result can be isolated prior to testing. Funding: E.S. is supported by the Crown Human Genome Center, Larson Charitable Foundation New Scientist Fund, Else Kroener Fresenius Foundation, White Rose International Foundation, Ben B. and Joyce E. Eisenberg Foundation, Nissenbaum Family, Marcos Pinheiro de Andrade and Vanessa Buchheim, Lady Michelle Michels, and Aliza Moussaieff and grants funded by the Minerva foundation with funding from the Federal German Ministry for Education and Research and by the European Research Council and the Israel Science Foundation. H.R. is supported by the Israeli Council for Higher Education (CHE) via the Weizmann Data Science Research Center and by a research grant from Madame Olga Klein – Astrachan
The impact of XENON100 and the LHC on Supersymmetric Dark Matter
The effect of 2010 and 2011 LHC data are discussed in connection to the
potential for the direct detection of supersymmetric dark matter. The impact of
the recent XENON100 results are contrasted to these predictions.Comment: 14 pages, 23 figures, To be published in the Proceedings of the 7th
DSU Conference, Beijing Chin
Colour reconnection in e+e- -> W+W- at sqrt(s) = 189 - 209 GeV
The effects of the final state interaction phenomenon known as colour
reconnection are investigated at centre-of-mass energies in the range sqrt(s) ~
189-209 GeV using the OPAL detector at LEP. Colour reconnection is expected to
affect observables based on charged particles in hadronic decays of W+W-.
Measurements of inclusive charged particle multiplicities, and of their angular
distribution with respect to the four jet axes of the events, are used to test
models of colour reconnection. The data are found to exclude extreme scenarios
of the Sjostrand-Khoze Type I (SK-I) model and are compatible with other
models, both with and without colour reconnection effects. In the context of
the SK-I model, the best agreement with data is obtained for a reconnection
probability of 37%. Assuming no colour reconnection, the charged particle
multiplicity in hadronically decaying W bosons is measured to be (nqqch) =
19.38+-0.05(stat.)+-0.08 (syst.).Comment: 30 pages, 9 figures, Submitted to Euro. Phys. J.
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