We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS ...HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.
The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting ...massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.
We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with a baseline energy resolution of σE = 3.86 ± 0.04 ( stat ) +0.19 −0.00 ( syst ) ...eV . This exclusion analysis sets the most stringent dark matter-nucleon scattering cross-section limits achieved by a cryogenic detector for dark matter particle masses from 93 to 140 MeV / c2 , with a raw exposure of 9.9 g d acquired at an above-ground facility. This work illustrates the scientific potential of detectors with athermal phonon sensors with eV-scale energy resolution for future dark matter searches.
We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event ...is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44}) cm^{2} at 46 GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^{2}.
Vogt-Koyanagi-Harada disease is due to an autoimmune reaction directed against melanocytes from the uvea, meninges, inner ear and the teguments which affects mainly colored populations with a female ...predominance. The disease starts with a brutal visual acuity loss due to diffuse acute choroiditis and retinal serous detachments, followed by a chronic phase characterized by recurrent bouts of anterior granulomatous uveitis, sub-clinical choroiditis and a poor visual prognosis. At this stage, typical skin symptoms such as vitiligo, poliosis or alopecia may be observed. Indocyanine green angiography and Enhanced Depth Imaging-OCT are very useful for the diagnosis and the follow-up. The goal of the treatment is to control the initial acute choroidal inflammation using aggressive treatment with steroids and immunosuppressive drugs, in order to completely heal the choroiditis and to prevent chronic complications.
The timing system for the CDF electromagnetic calorimeters Goncharov, M.; Kamon, T.; Khotilovich, V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2006, Letnik:
565, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We report on the design and performance of the electromagnetic calorimeter timing readout system (EMTiming) for the Collider Detector at Fermilab (CDF). The system will be used in searches for rare ...events with high-energy photons to verify that the photon is in time with the event collision, to reject cosmic-ray and beam-halo backgrounds, and to allow direct searches for new, heavy, long-lived neutral particles that decay to photons. The installation and commissioning of all 862 channels were completed in Fall 2004 as part of an upgrade to the Run II version of the detector. Using in situ data, including electrons from
W
→
e
ν
and
Z
→
ee
decays, we measure the energy threshold for a time to be recorded to be
3.8
±
0.3
GeV
(
1.9
±
0.1
GeV
)
in the central (plug) portion of the detector. Similarly, for the central (plug) portion we measure a timing resolution of
600
±
10
ps
(
610
±
10
ps
)
for electrons above 10
GeV (6
GeV). There are very few system pathologies such as recording a time when no energy is deposited, or recording a second, fake time for a single energy deposit.
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