Improved EDELWEISS-III sensitivity for low-mass WIMPs using a profile likelihood approach
EDELWEISS Collaboration, L. Hehn, E. Armengaud, Q. Arnaud, C. Augier, A. Benoît, L. Bergé, J. Billard, J. Blümer, T. de Boissière, A. Broniatowski, P. Camus, A.… 展开作者
EDELWEISS Collaboration, L. Hehn, E. Armengaud, Q. Arnaud, C. Augier, A. Benoît, L. Bergé, J. Billard, J. Blümer, T. de Boissière, A. Broniatowski, P. Camus, A. Cazes, M. Chapellier, F. Charlieux, M. De Jésus, L. Dumoulin, K. Eitel, N. Foerster, J. Gascon, A. Giuliani, M. Gros, G. Heuermann, Y. Jin, A. Juillard, C. Kéfélian, M. Kleifges, V. Kozlov, H. Kraus, V. A. Kudryavtsev, H. Le-Sueur, S. Marnieros, X. -F. Navick, C. Nones, E. Olivieri, P. Pari, B. Paul, M. -C. Piro, D. Poda, E. Queguiner, S. Rozov, V. Sanglard, B. Schmidt, S. Scorza, B. Siebenborn, D. Tcherniakhovski, L. Vagneron, M. Weber, E. Yakushev
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11 pages, 6 figures, 2 tables (updated to accepted version)
We report on a dark matter search for a Weakly Interacting Massive Particle (WIMP) in the mass range $m_χ\in [4, 30]\,\mathrm{GeV}/c^2$ with the EDELWEISS-III experiment. A 2D profile likelihood analysis is performed on data from eight selected detectors with the lowest energy thresholds leading to a combined fiducial exposure of 496 kg-days. External backgrounds from $γ$- and $β$-radiation, recoils from $^{206}$Pb and neutrons as well as detector intrinsic backgrounds were modelled from data outside the region of interest and constrained in the analysis. The basic data selection and most of the background models are the same as those used in a previously published analysis based on Boosted Decision Trees (BDT). For the likelihood approach applied in the analysis presented here, a larger signal efficiency and a subtraction of the expected background lead to a higher sensitivity, especially for the lowest WIMP masses probed. No statistically significant signal was found and upper limits on the spin-independent WIMP-nucleon scattering cross section can be set with a hypothesis test based on the profile likelihood test statistics. The 90% C.L. exclusion limit set for WIMPs with $m_χ= 4\,\mathrm{GeV/}c^2$ is $1.6 \times 10^{-39}\,\mathrm{cm^2}$, which is an improvement of a factor of seven with respect to the BDT-based analysis. For WIMP masses above $15\,\mathrm{GeV/}c^2$ the exclusion limits found with both analyses are in good agreement.
Combined Limits on WIMPs from the CDMS and EDELWEISS Experiments
CDMS和EDELWEISS的合作结合了他们使用低温锗探测器直接搜索暗物质的结果。总数据集代表614 kg.d当量接触。在实验之间交换数据之前，选择了一种简单的组合方法。结果解释的限制自旋无关的WIMP核子截面。对于质量为90 GeV/c^2的WIMP，这种分析是最灵敏的，在90% CL下排除了3.3 x 10^{-44} cm ^2的截面。在更高的WIMP质量下，这种组合使单个极限提高了1.6倍，高于700 GeV/c^2。结合数据的替代方法为WIMP质量的某些范围提供了更强的约束，而为其他范围提供了更弱的约束。
We consider the dark matter (DM) scenarios consisting of the mixture of WIMPs and PBHs and study how much fraction of the total DM can be PBHs. In such scenarios, PBHs can accrete the WIMPs and consequently enhance the heating and ionization in the intergalactic medium due to WIMP annihilations. We demonstrate that the CMB data can give the stringent bounds on the allowed PBH fraction which are comparable or even tighter than those from the gamma ray data depending on the DM masses. For instance, the MCMC likelihood analysis using the Planck CMB data leads to the bound on PBH DM fraction with …
We report the results of a search for the inelastic scattering of weakly interacting massive particles (WIMPs) in the XENON1T dark matter experiment. Scattering off $^{129}$Xe is the most sensitive probe of inelastic WIMP interactions, with a signature of a 39.6 keV de-excitation photon detected simultaneously with the nuclear recoil. Using an exposure of 0.89 tonne-years, we find no evidence of inelastic WIMP scattering with a significance of more than 2$σ$. A profile-likelihood ratio analysis is used to set upper limits on the cross-section of WIMP-nucleus interactions. We exclude new parame…
Dark Matter Search with the DEAP-3600 Detector using the Profile Likelihood Ratio Method
Carleton University（卡尔顿大学）；Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Queen’s University（阿瑟·B·麦克唐纳加拿大天体粒子物理研究所，女王大学）；Instituto de Física, Universidad Nacional Autónoma de México（墨西哥国立自治大学物理研究所）；TRIUMF（特里姆夫实验室）；Department of Physics, University of Alberta（阿尔伯塔大学物理系）；Rutherford Appleton Laboratory（卢瑟福·阿普尔顿实验室）；School of Natural Sciences, Laurentian University（劳伦森大学理学院）
We assess the status of a wide class of WIMP dark matter (DM) models in light of the latest experimental results using the global fitting framework $\textsf{GAMBIT}$. We perform a global analysis of effective field theory (EFT) operators describing the interactions between a gauge-singlet Dirac fermion and the Standard Model quarks, the gluons and the photon. In this bottom-up approach, we simultaneously vary the coefficients of 14 such operators up to dimension 7, along with the DM mass, the scale of new physics and several nuisance parameters. Our likelihood functions include the latest data…
CDMSlite Run 2 was a search for weakly interacting massive particles (WIMPs) with a cryogenic 600 g Ge detector operated in a high-voltage mode to optimize sensitivity to WIMPs of relatively low mass from 2 - 20 GeV/$c^2$. In this article, we present an effective field theory (EFT) analysis of the CDMSlite Run 2 data using an extended energy range and a comprehensive treatment of the expected background. A binned likelihood Bayesian analysis was performed on the recoil energy data, taking into account the parameters of the EFT interactions and optimizing the data selection with respect to the …
We report here the results of an Effective Field Theory (EFT) WIMP search analysis using LUX data. We build upon previous LUX analyses by extending the search window to include nuclear recoil energies up to $\sim$180 keV$_{nr}$, requiring a reassessment of data quality cuts and background models. In order to use a binned Profile Likelihood statistical framework, the development of new analysis techniques to account for higher-energy backgrounds was required. With a 3.14$\times10^4$ kg$\cdot$day exposure using data collected between 2014 and 2016, we set 90\% C.L. exclusion limits on non-relati…
We report on a search for Weakly Interacting Massive Particles (WIMPs) using 278.8 days of data collected with the XENON1T experiment at LNGS. XENON1T utilizes a liquid xenon time projection chamber with a fiducial mass of $(1.30 \pm 0.01)$ t, resulting in a 1.0 t$\times$yr exposure. The energy region of interest, [1.4, 10.6] $\mathrm{keV_{ee}}$ ([4.9, 40.9] $\mathrm{keV_{nr}}$), exhibits an ultra-low electron recoil background rate of $(82\substack{+5 \\ -3}\textrm{ (sys)}\pm3\textrm{ (stat)})$ events/$(\mathrm{t}\times\mathrm{yr}\times\mathrm{keV_{ee}})$. No significant excess over backgroun…
We report the first dark matter search results from XENON1T, a $\sim$2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042$\pm$12) kg fiducial mass and in the [5, 40] $\mathrm{keV}_{\mathrm{nr}}$ energy range of interest for WIMP dark matter searches, the electronic recoil background was $(1.93 \pm 0.25) \times 10^{-4}$ events/(kg $\times$ day $\times \…
We provide an updated and improved study of the prospects of the H.E.S.S. and Cherenkov Telescope Array (CTA) experiments in testing neutralino dark matter in the Minimal Supersymmetric Standard Model with nine free parameters (p9MSSM). We include all relevant experimental constraints and theoretical developments, in particular the calculation of the Sommerfeld enhancement for both present-day annihilation and the relic abundance. We perform a state-of-the-art analysis of the CTA sensitivity with a log-likelihood test ratio statistics and apply it to a numerical scan of the p9MSSM parameter sp…
