536 research outputs found
Progressing social prescribing with a focus on process of connection : evidence-informed guidance for robust evaluation and evidence synthesis
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Sensitivity of the IceCube Detector to Astrophysical Sources of High Energy Muon Neutrinos
We present the results of a Monte-Carlo study of the sensitivity of the
planned IceCube detector to predicted fluxes of muon neutrinos at TeV to PeV
energies. A complete simulation of the detector and data analysis is used to
study the detector's capability to search for muon neutrinos from sources such
as active galaxies and gamma-ray bursts. We study the effective area and the
angular resolution of the detector as a function of muon energy and angle of
incidence. We present detailed calculations of the sensitivity of the detector
to both diffuse and pointlike neutrino emissions, including an assessment of
the sensitivity to neutrinos detected in coincidence with gamma-ray burst
observations. After three years of datataking, IceCube will have been able to
detect a point source flux of E^2*dN/dE = 7*10^-9 cm^-2s^-1GeV at a 5-sigma
significance, or, in the absence of a signal, place a 90% c.l. limit at a level
E^2*dN/dE = 2*10^-9 cm^-2s^-1GeV. A diffuse E-2 flux would be detectable at a
minimum strength of E^2*dN/dE = 1*10^-8 cm^-2s^-1sr^-1GeV. A gamma-ray burst
model following the formulation of Waxman and Bahcall would result in a 5-sigma
effect after the observation of 200 bursts in coincidence with satellite
observations of the gamma-rays.Comment: 33 pages, 13 figures, 6 table
On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes
The sensitivity of a search for sources of TeV neutrinos can be improved by
grouping potential sources together into generic classes in a procedure that is
known as source stacking. In this paper, we define catalogs of Active Galactic
Nuclei (AGN) and use them to perform a source stacking analysis. The grouping
of AGN into classes is done in two steps: first, AGN classes are defined, then,
sources to be stacked are selected assuming that a potential neutrino flux is
linearly correlated with the photon luminosity in a certain energy band (radio,
IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino
production in AGN, this correlation is motivated by hadronic AGN models, as
briefly reviewed in this paper.
The source stacking search for neutrinos from generic AGN classes is
illustrated using the data collected by the AMANDA-II high energy neutrino
detector during the year 2000. No significant excess for any of the suggested
groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic
Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider
This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)
Measurement of the B0-anti-B0-Oscillation Frequency with Inclusive Dilepton Events
The - oscillation frequency has been measured with a sample of
23 million \B\bar B pairs collected with the BABAR detector at the PEP-II
asymmetric B Factory at SLAC. In this sample, we select events in which both B
mesons decay semileptonically and use the charge of the leptons to identify the
flavor of each B meson. A simultaneous fit to the decay time difference
distributions for opposite- and same-sign dilepton events gives ps.Comment: 7 pages, 1 figure, submitted to Physical Review Letter
On the stability of scalar-vacuum space-times
We study the stability of static, spherically symmetric solutions to the
Einstein equations with a scalar field as the source. We describe a general
methodology of studying small radial perturbations of scalar-vacuum
configurations with arbitrary potentials V(\phi), and in particular space-times
with throats (including wormholes), which are possible if the scalar is
phantom. At such a throat, the effective potential for perturbations V_eff has
a positive pole (a potential wall) that prevents a complete perturbation
analysis. We show that, generically, (i) V_eff has precisely the form required
for regularization by the known S-deformation method, and (ii) a solution with
the regularized potential leads to regular scalar field and metric
perturbations of the initial configuration. The well-known conformal mappings
make these results also applicable to scalar-tensor and f(R) theories of
gravity. As a particular example, we prove the instability of all static
solutions with both normal and phantom scalars and V(\phi) = 0 under spherical
perturbations. We thus confirm the previous results on the unstable nature of
anti-Fisher wormholes and Fisher's singular solution and prove the instability
of other branches of these solutions including the anti-Fisher "cold black
holes".Comment: 18 pages, 5 figures. A few comments and references added. Final
version accepted at EPJ
Genome-wide association for major depressive disorder: a possible role for the presynaptic protein piccolo
Major depressive disorder (MDD) is a common complex trait with enormous public health significance. As part of the Genetic Association Information Network initiative of the US Foundation for the National Institutes of Health, we conducted a genome-wide association study of 435 291 single nucleotide polymorphisms (SNPs) genotyped in 1738 MDD cases and 1802 controls selected to be at low liability for MDD. Of the top 200, 11 signals localized to a 167 kb region overlapping the gene piccolo (PCLO, whose protein product localizes to the cytomatrix of the presynaptic active zone and is important in monoaminergic neurotransmission in the brain) with P-values of 7.7 × 1
DES13S2cmm: the first superluminous supernova from the Dark Energy Survey
We present DES13S2cmm, the first spectroscopically-confirmed superluminous
supernova (SLSN) from the Dark Energy Survey (DES). We briefly discuss the data
and search algorithm used to find this event in the first year of DES
operations, and outline the spectroscopic data obtained from the European
Southern Observatory (ESO) Very Large Telescope to confirm its redshift (z =
0.663 +/- 0.001 based on the host-galaxy emission lines) and likely spectral
type (type I). Using this redshift, we find M_U_peak = -21.05 +0.10 -0.09 for
the peak, rest-frame U-band absolute magnitude, and find DES13S2cmm to be
located in a faint, low metallicity (sub-solar), low stellar-mass host galaxy
(log(M/M_sun) = 9.3 +/- 0.3); consistent with what is seen for other SLSNe-I.
We compare the bolometric light curve of DES13S2cmm to fourteen similarly
well-observed SLSNe-I in the literature and find it possesses one of the
slowest declining tails (beyond +30 days rest frame past peak), and is the
faintest at peak. Moreover, we find the bolometric light curves of all SLSNe-I
studied herein possess a dispersion of only 0.2-0.3 magnitudes between +25 and
+30 days after peak (rest frame) depending on redshift range studied; this
could be important for 'standardising' such supernovae, as is done with the
more common type Ia. We fit the bolometric light curve of DES13S2cmm with two
competing models for SLSNe-I - the radioactive decay of 56Ni, and a magnetar -
and find that while the magnetar is formally a better fit, neither model
provides a compelling match to the data. Although we are unable to conclusively
differentiate between these two physical models for this particular SLSN-I,
further DES observations of more SLSNe-I should break this degeneracy,
especially if the light curves of SLSNe-I can be observed beyond 100 days in
the rest frame of the supernova.Comment: Accepted by MNRAS (2015 January 23), 13 pages, 6 figures, 2 table
Properties of the Top Quark
The top quark was discoverd at the CDF and D0 experiments in 1995. As the
partner of the bottom quark its properties within the Standard Model are fully
defined. Only the mass is a free parameter. The measurement of the top quark
mass and the verification of the expected properties have been an important
topic of experimental top quark physics since. In this review the recent
results on top quark properties obtained by the Tevatron experiments CDF and D0
are summarised. At the advent of the LHC special emphasis is given to the basic
measurement methods and the dominating systematic uncertainties.Comment: Habilitation thesis, revised and updated for publication in EPJ
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