33 research outputs found
A Search for Z=-1 Dark Matter Annihilation Products in Cosmic Rays with AMS-01
The majority of mass in the universe has not been observed optically and is
termed dark matter. The supersymmetric neutralino provides an interesting dark
matter candidate, which may self-annihilate in our galaxy, producing particles
visible in the cosmic ray spectrum. During a ten day space shuttle flight, the
AMS-01 detector recorded over 100 million cosmic ray events. This analysis
searches for the products of neutralino annihilation in the AMS-01 Z=-1
spectrum, and uses the results to place limits on which supersymmetric and dark
matter halo distribution models are compatible.Comment: Thesi
Report of the Topical Group on Wave Dark Matter for Snowmass 2021
There is a strong possibility that the particles making up the dark matter in
the Universe have a mass below 1 eV and in many important situations exhibit a
wave-like behavior. Amongst the candidates the axion stands out as particularly
well motivated but other possibilities such as axion-like particles, light
scalars and light vectors, should be seriously investigated with both
experiments and theory. Discovery of any of these dark matter particles would
be revolutionary. The wave-like nature opens special opportunities to gain
precise information on the particle properties a well as astrophysical
information on dark matter shortly after a first detection. To achieve these
goals requires continued strong support for the next generations of axion
experiments to probe significant axion parameter space this decade and to
realize the vision of a definitive axion search program in the next 20 years.
This needs to be complemented by strong and flexible support for a broad range
of smaller experiments, sensitive to the full variety of wave-like dark matter
candidates. These have their own discovery potential but can also be the test
bed for future larger scale searches. Strong technological support not only
allows for the optimal realization of the current and near future experiments
but new technologies such as quantum measurement and control can also provide
the next evolutionary jump enabling a broader and deeper sensitivity. Finally,
a theory effort ranging from fundamental model building over investigating
phenomenological constraints to the conception of new experimental techniques
is a cornerstone of the current rapid developments in the search for wave-like
dark matter and should be strengthened to have a solid foundation for the
future.Comment: First arXiv version for community feedbac
The Palomar Testbed Interferometer Calibrator Catalog
The Palomar Testbed Interferometer (PTI) archive of observations between 1998
and 2005 is examined for objects appropriate for calibration of optical
long-baseline interferometer observations - stars that are predictably
point-like and single. Approximately 1,400 nights of data on 1,800 objects were
examined for this investigation. We compare those observations to an
intensively studied object that is a suitable calibrator, HD217014, and
statistically compare each candidate calibrator to that object by computing
both a Mahalanobis distance and a Principal Component Analysis. Our hypothesis
is that the frequency distribution of visibility data associated with
calibrator stars differs from non-calibrator stars such as binary stars.
Spectroscopic binaries resolved by PTI, objects known to be unsuitable for
calibrator use, are similarly tested to establish detection limits of this
approach. From this investigation, we find more than 350 observed stars
suitable for use as calibrators (with an additional being
rejected), corresponding to sky coverage for PTI. This approach
is noteworthy in that it rigorously establishes calibration sources through a
traceable, empirical methodology, leveraging the predictions of spectral energy
distribution modeling but also verifying it with the rich body of PTI's on-sky
observations.Comment: 100 pages, 7 figures, 7 tables; to appear in the May 2008ApJS, v176n
US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report
This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in
Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference
Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome