Measurement of Coherent Elastic Neutrino-Nucleus Scattering from reactor antineutrinos

The 96.4 day exposure of a 3 kg ultra-low noise germanium detector to the high flux of antineutrinos from a power nuclear reactor is described. A very strong preference ($p<1.2\times10^{-3}$) for the presence of a coherent elastic neutrino-nucleus scattering (CE$\nu$NS) component in the data is found, when compared to a background-only model. No such effect is visible in 25 days of operation during reactor outages. The best-fit CE$\nu$NS signal is in good agreement with expectations based on a recent characterization of germanium response to sub-keV nuclear recoils. Deviations of order 60\% from the Standard Model CE$\nu$NS prediction can be excluded using present data. Standing uncertainties in models of germanium quenching factor, neutrino energy spectrum, and background are examined.Comment: 6 pages, 5 figures. Data release and additional information in ancillary file

First results from a search for coherent elastic neutrino-nucleus scattering at a reactor site

The deployment of a low-noise 3 kg p-type point contact germanium detector at the Dresden-II power reactor, 8 meters from its $2.96  GW_{th}$ core, is described. This location provides an unprecedented (anti)neutrino flux of $8.1×10^{13}  \overline{v_e}/cm^2s$. When combined with the $0.2  keV_{ee}$ detector threshold achieved, a first measurement of $CE⁢⁢NS$ from a reactor source appears to be within reach. We report on the characterization and abatement of backgrounds during initial runs, deriving improved limits on extensions of the Standard Model involving a light vector mediator, from preliminary data

Experimental constraints on a dark matter origin for the DAMA annual modulation effect

A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type of germanium detector to conclusively rule out a standard isothermal galactic halo of Weakly Interacting Massive Particles (WIMPs) as the explanation for the annual modulation effect leading to the claim. Bounds are similarly imposed on a suggestion that dark pseudoscalars mightlead to the effect. We describe the sensitivity to light dark matter particles achievable with our device, in particular to Next-to-Minimal Supersymmetric Model candidates.Comment: v4: introduces recent results from arXiv:0807.3279 and arXiv:0807.2926. Sensitivity to pseudoscalars is revised in light of the first. Discussion on the subject adde

Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector

We report on several features present in the energy spectrum from an ultra low-noise germanium detector operated at 2,100 m.w.e. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss several possible causes for an irreducible excess of bulk-like events below 3 keVee, including a dark matter candidate common to the DAMA/LIBRA annual modulation effect, the hint of a signal in CDMS, and phenomenological predictions. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.Comment: 4 pages, 4 figures. v2: submitted version. Minimal changes in wording, one reference adde

Search for an Annual Modulation in a P-type Point Contact Germanium Dark Matter Detector

Fifteen months of cumulative CoGeNT data are examined for indications of an annual modulation, a predicted signature of Weakly Interacting Massive Particle (WIMP) interactions. Presently available data support the presence of a modulated component of unknown origin, with parameters prima facie compatible with a galactic halo composed of light-mass WIMPs. Unoptimized estimators yield a statistical significance for a modulation of ~2.8 sigma, limited by the short exposure.Comment: Published version, slightly expanded discussion of ROI uncertainties, one reference adde

Characterisation of a small electrode HPGe detector

© 2019 Elsevier B.V. Small electrode HPGe detectors in an inverted coaxial geometry are increasingly in use in applications where both high efficiency and excellent energy resolution are required. The unusual electric field configuration of these detectors results in extremely long charge collection times compared to planar and coaxial devices. In this work we have characterised such a detector using gamma-ray coincidence measurements and optimised an electric field simulation to reproduce the positional variation of detector response. We show that, alongside accurate crystal geometry and applied electric potential, a temperature correction is crucial to correctly determining appropriate charge carrier mobility parameters. This work will help to guide the future development of HPGE detectors for applications including radioactive waste assay, radio-isotope dating, and fundamental nuclear physics

Wars, Presidents and Popularity: The Political Cost(s) of War Re-Examined

Extensive research demonstrates that war casualties depress incumbent popularity. The present study argues that analyses of the political costs of warfare should also account for the financial toll of wars since a) financial costs of wars are substantial, b) these costs are publicly observed and understood and c) fiscal policy affects incumbents' approval ratings. Empirical evidence based on US data for the 1948-2008 period supports this theoretical claim: pecuniary costs of warfare either directly affect presidential popularity (e.g., in the Korean War) or their inclusion affects the predicted political cost of war casualties (e.g., in the Korean and Iraq/Afghanistan Wars). Interestingly, the adverse effect of war-spending is strongest under favourable economic conditions (i.e. low unemployment).Umfangreiche Forschungen zeigen, dass Kriegsopfer der Popularität des Amtsinhabers schaden. Die vorliegende Studie liefert Argumente dafür, dass Analysen der politischen Kosten der Kriegsführung in die Berechnung der finanziellen Kriegsausgaben miteinbezogen werden sollten, da a) die finanziellen Kosten von Kriegen beträchtlich sind, b) diese Kosten von der Öffentlichkeit wahrgenommen und verstanden werden, c) Fiskalpolitik die Umfragewerte des Amtsinhabers beeinflusst. Basierend auf US-Daten über den Zeitraum 1948-2008 wird dieser theoretische Anspruch empirisch unterstützt: pekuniäre Kosten der Kriegsführung haben entweder direkt eine Auswirkung auf die Popularität des Präsidenten (z. B. Koreakrieg) oder deren Einbeziehung beeinflusst die vorhergesagten politischen Kosten durch Kriegsopfer (z. B. Korea- und Irak/-Afghanistankrieg). Interessanterweise sind die negativen Auswirkungen der Kriegsausgaben am stärksten, wenn die wirtschaftlichen Bedingungen günstig (d.h. niedrige Arbeitslosigkeit) sind