42 research outputs found
Dark Matter in the Coming Decade: Complementary Paths to Discovery and Beyond
In this report we summarize the many dark matter searches currently being
pursued through four complementary approaches: direct detection, indirect
detection, collider experiments, and astrophysical probes. The essential
features of broad classes of experiments are described, each with their own
strengths and weaknesses. The complementarity of the different dark matter
searches is discussed qualitatively and illustrated quantitatively in two
simple theoretical frameworks. Our primary conclusion is that the diversity of
possible dark matter candidates requires a balanced program drawing from all
four approaches.Comment: Report prepared for the Community Summer Study (Snowmass) 2013, on
behalf of Cosmic Frontier Working Groups 1-4 (CF1: WIMP Dark Matter Direct
Detection, CF2: WIMP Dark Matter Indirect Detection, CF3: Non-WIMP Dark
Matter, and CF4: Dark Matter Complementarity); published versio
Causes of death among homeless people: a population-based cross-sectional study of linked hospitalisation and mortality data in England. [version 1; peer review: 2 approved]
Background: Homelessness has increased by 165% since 2010 in England, with evidence from many settings that those affected experience high levels of mortality. In this paper we examine the contribution of different causes of death to overall mortality in homeless people recently admitted to hospitals in England with specialist integrated homeless health and care (SIHHC) schemes. Methods: We undertook an analysis of linked hospital admission records and mortality data for people attending any one of 17 SIHHC schemes between 1st November 2013 and 30th November 2016. Our primary outcome was death, which we analysed in subgroups of 10th version international classification of disease (ICD-10) specific deaths; and deaths from amenable causes. We compared our results to a sample of people living in areas of high social deprivation (IMD5 group). Results: We collected data on 3,882 individual homeless hospital admissions that were linked to 600 deaths. The median age of death was 51.6 years (interquartile range 42.7-60.2) for SIHHC and 71.5 for the IMD5 (60.67-79.0). The top three underlying causes of death by ICD-10 chapter in the SIHHC group were external causes of death (21.7%; 130/600), cancer (19.0%; 114/600) and digestive disease (19.0%; 114/600). The percentage of deaths due to an amenable cause after age and sex weighting was 30.2% in the homeless SIHHC group (181/600) compared to 23.0% in the IMD5 group (578/2,512). Conclusion: Nearly one in three homeless deaths were due to causes amenable to timely and effective health care. The high burden of amenable deaths highlights the extreme health harms of homelessness and the need for greater emphasis on prevention of homelessness and early healthcare interventions
Outcomes of specialist discharge coordination and intermediate care schemes for patients who are homeless: analysis protocol for a population-based historical cohort
Introduction People who are homeless often experience poor hospital discharge arrangements, reflecting ongoing care and housing needs. Specialist integrated homeless health and care provision (SIHHC) schemes have been developed and implemented to facilitate the safe and timely discharge of homeless patients from hospital. Our study aims to investigate the health outcomes of patients who were homeless and seen by a selection of SIHHC services. Methods and analysis Our study will employ a historical population-based cohort in England. We will examine health outcomes among three groups of adults: (1) homeless patients seen by specialist discharge schemes during their hospital admission; (2) homeless patients not seen by a specialist scheme and (3)admitted patients who live in deprived neighbourhoods and were not recorded as being homeless. Primary outcomes will be: time from discharge to next hospital inpatient admission; time from discharge to next accident and emergency attendance and 28-day emergency readmission. Outcome data will be generated through linkage to hospital admissions data (Hospital Episode Statistics) and mortality data for November 2013 to November 2016. Multivariable regression will be used to model the relationship between the study comparison groups and each of the outcomes. Ethics and dissemination Approval has been obtained from the National Health Service (NHS) Confidentiality Advisory Group (reference 16/CAG/0021) to undertake this work using unconsented identifiable data. Health Research Authority Research Ethics approval (REC 16/EE/0018) has been obtained in addition to local research and development approvals for data collection at NHS sites. We will feedback the results of our study to our advisory group of people who have lived experience of homelessness and seek their suggestions on ways to improve or take this work further for their benefit. We will disseminate our findings to SIHHC schemes through a series of regional workshops
TeV String State Excitation via High Energy Cosmic Neutrinos
We construct the open-string scattering amplitudes for neutrino-gluon
collisions and evaluate the high energy neutrino-nucleon scattering cross
section via string state excitations in the TeV string-scale scenario. We find
that the neutrino-gluon scattering is the dominant contribution, 5-10 times
larger than neutrino-quark processes, though black hole production may be
larger than the string contribution at higher energies. We illustrate the
observability of the string signal at the Auger Observatory and the IceCube
neutrino telescope for a string scale about 1 TeV.Comment: version to appear in PL
A Leptophobic Z' And Dark Matter From Grand Unification
We explore the phenomenology of Grand Unified Models based on the E_6 group,
focusing on the Z' with suppressed couplings to leptons that can appear in such
models. We find that this Z' can accommodate the W+dijets anomaly reported by
the CDF collaboration. Furthermore, a viable dark matter candidate in the form
of a right-handed sneutrino is also present within the fundamental
27-dimensional representation of E_6. Through its sizable couplings to the Z',
the dark matter is predicted to possess an elastic scattering cross section
with neutrons which can generate the signals reported by the CoGeNT and
DAMA/LIBRA collaborations. To avoid being overproduced in the early universe,
the dark matter must annihilate to leptons through the exchange of charged or
neutral fermions which appear in the 27 of E_6, providing an excellent fit to
the gamma ray spectrum observed from the Galactic Center by the Fermi Gamma Ray
Space Telescope.Comment: 6 pages, 2 figur
GJ 3236: a new bright, very low-mass eclipsing binary system discovered by the MEarth observatory
We report the detection of eclipses in GJ 3236, a bright (I = 11.6) very low
mass binary system with an orbital period of 0.77 days. Analysis of light- and
radial velocity curves of the system yielded component masses of 0.38 +/- 0.02
and 0.28 +/- 0.02 Msol. The central values for the stellar radii are larger
than the theoretical models predict for these masses, in agreement with the
results for existing eclipsing binaries, although the present 5% observational
uncertainties limit the significance of the larger radii to approximately 1
sigma. Degeneracies in the light curve models resulting from the unknown
configuration of surface spots on the components of GJ 3236 currently dominate
the uncertainties in the radii, and could be reduced by obtaining precise,
multi-band photometry covering the full orbital period. The system appears to
be tidally synchronized and shows signs of high activity levels as expected for
such a short orbital period, evidenced by strong Halpha emission lines in the
spectra of both components. These observations probe an important region of
mass-radius parameter space around the predicted transition to fully-convective
stellar interiors, where there are a limited number of precise measurements
available in the literature.Comment: 14 pages, 5 figures, 10 tables, emulateapj format. Accepted for
publication in Ap
Detecting Microscopic Black Holes with Neutrino Telescopes
If spacetime has more than four dimensions, ultra-high energy cosmic rays may
create microscopic black holes. Black holes created by cosmic neutrinos in the
Earth will evaporate, and the resulting hadronic showers, muons, and taus may
be detected in neutrino telescopes below the Earth's surface. We simulate such
events in detail and consider black hole cross sections with and without an
exponential suppression factor. We find observable rates in both cases: for
conservative cosmogenic neutrino fluxes, several black hole events per year are
observable at the IceCube detector; for fluxes at the Waxman-Bahcall bound,
tens of events per year are possible. We also present zenith angle and energy
distributions for all three channels. The ability of neutrino telescopes to
differentiate hadrons, muons, and possibly taus, and to measure these
distributions provides a unique opportunity to identify black holes, to
experimentally constrain the form of black hole production cross sections, and
to study Hawking evaporation.Comment: 20 pages, 9 figure
The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
We present the fifth edition of the Sloan Digital Sky Survey (SDSS) Quasar
Catalog, which is based upon the SDSS Seventh Data Release. The catalog, which
contains 105,783 spectroscopically confirmed quasars, represents the conclusion
of the SDSS-I and SDSS-II quasar survey. The catalog consists of the SDSS
objects that have luminosities larger than M_i = -22.0 (in a cosmology with H_0
= 70 km/s/Mpc Omega_M = 0.3, and Omega_Lambda = 0.7) have at least one emission
line with FWHM larger than 1000 km/s or have interesting/complex absorption
features, are fainter than i > 15.0 and have highly reliable redshifts. The
catalog covers an area of 9380 deg^2. The quasar redshifts range from 0.065 to
5.46, with a median value of 1.49; the catalog includes 1248 quasars at
redshifts greater than four, of which 56 are at redshifts greater than five.
The catalog contains 9210 quasars with i < 18; slightly over half of the
entries have i< 19. For each object the catalog presents positions accurate to
better than 0.1" rms per coordinate, five-band (ugriz) CCD-based photometry
with typical accuracy of 0.03 mag, and information on the morphology and
selection method. The catalog also contains radio, near-infrared, and X-ray
emission properties of the quasars, when available, from other large-area
surveys. The calibrated digital spectra cover the wavelength region 3800-9200
Ang. at a spectral resolution R = 2000 the spectra can be retrieved from the
SDSS public database using the information provided in the catalog. Over 96% of
the objects in the catalog were discovered by the SDSS. We also include a
supplemental list of an additional 207 quasars with SDSS spectra whose archive
photometric information is incomplete.Comment: Accepted, to appear in AJ, 7 figures, electronic version of Table 2
is available, see
http://www.sdss.org/dr7/products/value_added/qsocat_dr7.htm
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years