1,399 research outputs found
Coherent Neutrino Scattering in Dark Matter Detectors
Coherent elastic neutrino- and WIMP-nucleus interaction signatures are
expected to be quite similar. This paper discusses how a next generation
ton-scale dark matter detector could discover neutrino-nucleus coherent
scattering, a precisely-predicted Standard Model process. A high intensity
pion- and muon- decay-at-rest neutrino source recently proposed for oscillation
physics at underground laboratories would provide the neutrinos for these
measurements. In this paper, we calculate raw rates for various target
materials commonly used in dark matter detectors and show that discovery of
this interaction is possible with a 2 tonyear GEODM exposure in an
optimistic energy threshold and efficiency scenario. We also study the effects
of the neutrino source on WIMP sensitivity and discuss the modulated neutrino
signal as a sensitivity/consistency check between different dark matter
experiments at DUSEL. Furthermore, we consider the possibility of coherent
neutrino physics with a GEODM module placed within tens of meters of the
neutrino source.Comment: 8 pages, 4 figure
Measuring Active-to-Sterile Neutrino Oscillations with Neutral Current Coherent Neutrino-Nucleus Scattering
Light sterile neutrinos have been introduced as an explanation for a number
of oscillation signals at eV. Neutrino oscillations at
relatively short baselines provide a probe of these possible new states. This
paper describes an accelerator-based experiment using neutral current coherent
neutrino-nucleus scattering to strictly search for active-to-sterile neutrino
oscillations. This experiment could, thus, definitively establish the existence
of sterile neutrinos and provide constraints on their mixing parameters. A
cyclotron-based proton beam can be directed to multiple targets, producing a
low energy pion and muon decay-at-rest neutrino source with variable distance
to a single detector. Two types of detectors are considered: a germanium-based
detector inspired by the CDMS design and a liquid argon detector inspired by
the proposed CLEAR experiment.Comment: 10 pages, 7 figure
Plasma Processing of Large Curved Surfaces for SRF Cavity Modification
Plasma based surface modification of niobium is a promising alternative to
wet etching of superconducting radio frequency (SRF) cavities. The development
of the technology based on Cl2/Ar plasma etching has to address several crucial
parameters which influence the etching rate and surface roughness, and
eventually, determine cavity performance. This includes dependence of the
process on the frequency of the RF generator, gas pressure, power level, the
driven (inner) electrode configuration, and the chlorine concentration in the
gas mixture during plasma processing. To demonstrate surface layer removal in
the asymmetric non-planar geometry, we are using a simple cylindrical cavity
with 8 ports symmetrically distributed over the cylinder. The ports are used
for diagnosing the plasma parameters and as holders for the samples to be
etched. The etching rate is highly correlated with the shape of the inner
electrode, radio-frequency (RF) circuit elements, chlorine concentration in the
Cl2/Ar gas mixtures, residence time of reactive species and temperature of the
cavity. Using cylindrical electrodes with variable radius, large-surface
ring-shaped samples and d.c. bias implementation in the external circuit we
have demonstrated substantial average etching rates and outlined the
possibility to optimize plasma properties with respect to maximum surface
processing effect
EXPLORATORY TESTS ON POSSIBLE INJURIOUS AFTER EFFECTS OF PIGEON PEAS ON SUBSEQUENT CROPS
EXPLORATORY TESTS ON POSSIBLE INJURIOUS AFTER EFFECTS OF PIGEON PEAS ON SUBSEQUENT CROP
Adipose Tissue Distribution and Survival Among Women with Nonmetastatic Breast Cancer.
ObjectivePrevious studies of breast cancer survival have not considered specific depots of adipose tissue such as subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT).MethodsThis study assessed these relationships among 3,235 women with stage II and III breast cancer diagnosed between 2005 and 2013 at Kaiser Permanente Northern California and between 2000 and 2012 at Dana Farber Cancer Institute. SAT and VAT areas (in centimeters squared) were calculated from routine computed tomography scans within 6 (median: 1.2) months of diagnosis, covariates were collected from electronic health records, and vital status was assessed by death records. Hazard ratios (HRs) and 95% CIs were estimated using Cox regression.ResultsSAT and VAT ranged from 19.0 to 891 cm2 and from 0.484 to 454 cm2 , respectively. SAT was related to increased risk of death (127-cm2 increase; HR [95% CI]: 1.13 [1.02-1.26]), but no relationship was found with VAT (78.18-cm2 increase; HR [95% CI]: 1.02 [0.91-1.14]). An association with VAT was noted among women with stage II cancer (stage II: HR: 1.17 [95% CI: 0.99-1.39]; stage III: HR: 0.90 [95% CI: 0.76-1.07]; P interaction < 0.01). Joint increases in SAT and VAT were associated with mortality above either alone (simultaneous 1-SD increase: HR 1.19 [95% CI: 1.05-1.34]).ConclusionsSAT may be an underappreciated risk factor for breast cancer-related death
New Physics effects in the flavor-changing neutral couplings of the Top quark
We survey the flavor-changing neutral couplings (FCNC) of the top quark
predicted by some extensions of the Standard Model: THDM, SUSY, L-R symmetric,
TC2, 331, and models with extra quarks. Since the expected sensitivity of the
LHC and ILC for the tcV (V=\gamma,g,Z) and tcH couplings is of order of a few
percent, we emphasize the importance of any new physics effect that gives a
prediction for these FCNC couplings within this limit. We also review the
constraints imposed on these couplings from low-energy precision measurements.Comment: 19 pages, 7 figures. Accepted as a review paper in Int. J. of Mod.
Phys.
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