7 research outputs found
Discovery prospects with the Dark-photons & Axion-Like particles Interferometer
We discuss the discovery potential of the Dark-photons & Axion-Like particles
Interferometer (DALI) in this letter. The apparatus, currently in a design and
prototyping phase, will probe axion dark matter from the Teide Observatory, an
environment protected from terrestrial microwave sources, reaching
Dine--Fischler--Srednicki--Zhitnitsky-like axion sensitivity in the range
25--250 eV of mass. The experimental approach shows a potential to probe
dark sector photons of kinetic mixing strength in excess of several ,
and to establish new constraints to a stochastic gravitational wave background
in its band. We identify different branches, including cosmology, stellar, and
particle physics, where this next-generation halo-telescope may play a role in
coming years.Comment: As accepted by PRD [8 pages, 5 figures + Supplemental Material 4
pages, 3 figures].
https://journals.aps.org/prd/accepted/1f074Q62Pa91023535875f66ca556bf86dda6f46
Experimental measurement of the quality factor of a Fabry-P\'erot open-cavity axion haloscope
The axion is a hypothetical boson arising from the most natural solution to
the problem of charge and parity symmetry in the strong nuclear force.
Moreover, this pseudoscalar emerges as a dark matter candidate in a parameter
space extending several decades in mass. The Dark-photons \& Axion-Like
particles Interferometer (DALI) is a proposal to search for axion dark matter
in a range that remains under-examined. Currently in a design and prototyping
phase, this haloscope is a multilayer Fabry-P\'erot interferometer. A
proof-of-principle experiment is performed to observe the resonance in a
prototype. The test unveils a quality factor per open cavity of a few hundred
over a bandwidth of the order of dozens of megahertz. The result elucidates a
physics potential to find the, so far elusive, axion, in a sector which can
simultaneously solve the symmetry problem in the strong interaction and the
enigma of dark matter.Comment: 5 pages, 6 figure
HARMONI at ELT: project status and instrument overview
International audienceHARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450 nm to 2450 nm with resolving powers from 3500 to 18000 and spatial sampling from 60 mas to 4 mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade. The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this paper, we provide an overview of the instrument's capabilities, details of recent technical changes during the red flag period, and an update of sensitivities
A Forecast of the Sensitivity of the DALI Experiment to Galactic Axion Dark Matter
The axion is a long-postulated boson that can simultaneously solve two fundamental problems of modern physics: the charge–parity symmetry problem in the strong interaction and the enigma of dark matter. In this work, we estimate, by means of Monte Carlo simulations, the sensitivity of the Dark-photons & Axion-Like particles Interferometer (DALI), a new-generation Fabry–Pérot haloscope proposed to probe axion dark matter in the 25–250 μeV band
HARMONI at ELT: overview of the capabilities and expected performance of the ELT's first light, adaptive optics assisted integral field spectrograph.
International audienc
Switching TNF antagonists in patients with chronic arthritis: An observational study of 488 patients over a four-year period
The objective of this work is to analyze the survival of infliximab, etanercept and adalimumab in patients who have switched among tumor necrosis factor (TNF) antagonists for the treatment of chronic arthritis. BIOBADASER is a national registry of patients with different forms of chronic arthritis who are treated with biologics. Using this registry, we have analyzed patient switching of TNF antagonists. The cumulative discontinuation rate was calculated using the actuarial method. The log-rank test was used to compare survival curves, and Cox regression models were used to assess independent factors associated with discontinuing medication. Between February 2000 and September 2004, 4,706 patients were registered in BIOBADASER, of whom 68% had rheumatoid arthritis, 11% ankylosing spondylitis, 10% psoriatic arthritis, and 11% other forms of chronic arthritis. One- and two-year drug survival rates of the TNF antagonist were 0.83 and 0.75, respectively. There were 488 patients treated with more than one TNF antagonist. In this situation, survival of the second TNF antagonist decreased to 0.68 and 0.60 at 1 and 2 years, respectively. Survival was better in patients replacing the first TNF antagonist because of adverse events (hazard ratio (HR) for discontinuation 0.55 (95% confidence interval (CI), 0.34-0.84)), and worse in patients older than 60 years (HR 1.10 (95% CI 0.97-2.49)) or who were treated with infliximab (HR 3.22 (95% CI 2.13-4.87)). In summary, in patients who require continuous therapy and have failed to respond to a TNF antagonist, replacement with a different TNF antagonist may be of use under certain situations. This issue will deserve continuous reassessment with the arrival of new medications. © 2006 Gomez-Reino and Loreto Carmona; licensee BioMed Central Ltd