Author
S. Scholl
Bio: S. Scholl is an academic researcher from University of Tübingen. The author has contributed to research in topics: Dark matter & European Underground Rare Event Calorimeter Array. The author has an hindex of 18, co-authored 49 publications receiving 3026 citations.
Papers
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TL;DR: The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011 as mentioned in this paper.
Abstract: The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds.
820 citations
TL;DR: In this article, the authors present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light.
Abstract: The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO$_4$ crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds. Sixty-seven events are found in the acceptance region where a WIMP signal in the form of low energy nuclear recoils would be expected. We estimate background contributions to this observation from four sources: 1) "leakage" from the e/\gamma-band 2) "leakage" from the \alpha-particle band 3) neutrons and 4) Pb-206 recoils from Po-210 decay. Using a maximum likelihood analysis, we find, at a high statistical significance, that these sources alone are not sufficient to explain the data. The addition of a signal due to scattering of relatively light WIMPs could account for this discrepancy, and we determine the associated WIMP parameters.
697 citations
Jamia Millia Islamia1, Vietnam Academy of Science and Technology2, Hanoi University of Science3, Saitama University4, Aarhus University5, University of California, Santa Barbara6, Commissariat à l'énergie atomique et aux énergies alternatives7, University of Münster8, University of Connecticut9, University of Manchester10, Indian Institute of Technology Guwahati11, Leiden University12, Northwestern University13, Federal University of Paraíba14, Centre national de la recherche scientifique15, Universidade Federal do ABC16, University of Southampton17, Argonne National Laboratory18, Karlsruhe Institute of Technology19, University of Mainz20, Technische Universität München21, Max Planck Society22, Heidelberg University23, University of Tübingen24, Massachusetts Institute of Technology25, Durham University26, University of California, San Diego27, C. N. Yang Institute for Theoretical Physics28, Russian Academy of Sciences29, Moscow Institute of Physics and Technology30, University of Sydney31, University of Copenhagen32, Université libre de Bruxelles33, Paris Diderot University34, Niels Bohr Institute35, Estácio S.A.36, CERN37, University of California, Santa Cruz38, Institute on Taxation and Economic Policy39, University of Bern40, Institute for Advanced Study41, RWTH Aachen University42, Chinese Academy of Sciences43, East China University of Science and Technology44, University of Chicago45, Autonomous University of Madrid46, King's College London47, INAF48, Lawrence Berkeley National Laboratory49, University of Bari50, Istituto Nazionale di Fisica Nucleare51, University of Geneva52, Petersburg Nuclear Physics Institute53, University of Genoa54, Kapteyn Astronomical Institute55, Fermilab56, Spanish National Research Council57, Oak Ridge National Laboratory58, University of California, Berkeley59, École Polytechnique Fédérale de Lausanne60, University of Paris61, University of Zurich62, Mitchell Institute63, Tohoku University64, Princeton University65, Shimane University66, University of Maryland, College Park67, Dresden University of Technology68
TL;DR: A comprehensive review of keV-scale neutrino Dark Matter can be found in this paper, where the role of active neutrinos in particle physics, astrophysics, and cosmology is reviewed.
Abstract: We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved—cosmology, astrophysics, nuclear, and particle physics—in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.
398 citations
TL;DR: In this paper, the authors present results from a low-threshold analysis of a single upgraded detector module, which efficiently vetoes low energy backgrounds induced by α-decays on inner surfaces of the detector.
Abstract: The CRESST-II cryogenic dark matter search aims for the detection of WIMPs via elastic scattering off nuclei in CaWO$_4$ crystals. We present results from a low-threshold analysis of a single upgraded detector module. This module efficiently vetoes low energy backgrounds induced by $\alpha$-decays on inner surfaces of the detector. With an exposure of \unit[29.35]{kg live days} collected in 2013 we set a limit on spin-independent WIMP-nucleon scattering which probes a new region of parameter space for WIMP masses below \unit[3]{GeV/c$^2$}, previously not covered in direct detection searches. A possible excess over background discussed for the previous CRESST-II phase 1 (from 2009 to 2011) is not confirmed.
235 citations
TL;DR: In this paper, the authors present results from a low-threshold analysis of a single upgraded detector module, which efficiently vetoes low energy backgrounds induced by $$\alpha $$¯¯ -decays on inner surfaces of the detector.
Abstract: The CRESST-II cryogenic dark matter search aims for the detection of WIMPs via elastic scattering off nuclei in CaWO
$$_4$$
crystals. We present results from a low-threshold analysis of a single upgraded detector module. This module efficiently vetoes low energy backgrounds induced by $$\alpha $$
-decays on inner surfaces of the detector. With an exposure of 29.35 kg live days collected in 2013 we set a limit on spin-independent WIMP-nucleon scattering which probes a new region of parameter space for WIMP masses below 3 GeV/c
$$^2$$
, previously not covered in direct detection searches. A possible excess over background discussed for the previous CRESST-II phase 1 (from 2009 to 2011) is not confirmed.
204 citations
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TL;DR: For example, the observed cores of many dark-matter dominated galaxies are both less dense and less cuspy than naively predicted in the Lambda$CDM as discussed by the authors, and the number of small galaxies and dwarf satellites in the Local Group is far below the predicted count of low-mass dark matter halos and subhalos within similar volumes.
Abstract: The dark energy plus cold dark matter ($\Lambda$CDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of Universe and its evolution with time. Yet on length scales smaller than $\sim 1$ Mpc and mass scales smaller than $\sim 10^{11} M_{\odot}$, the theory faces a number of challenges. For example, the observed cores of many dark-matter dominated galaxies are both less dense and less cuspy than naively predicted in $\Lambda$CDM. The number of small galaxies and dwarf satellites in the Local Group is also far below the predicted count of low-mass dark matter halos and subhalos within similar volumes. These issues underlie the most well-documented problems with $\Lambda$CDM: Cusp/Core, Missing Satellites, and Too-Big-to-Fail. The key question is whether a better understanding of baryon physics, dark matter physics, or both will be required to meet these challenges. Other anomalies, including the observed planar and orbital configurations of Local Group satellites and the tight baryonic/dark matter scaling relations obeyed by the galaxy population, have been less thoroughly explored in the context of $\Lambda$CDM theory. Future surveys to discover faint, distant dwarf galaxies and to precisely measure their masses and density structure hold promising avenues for testing possible solutions to the small-scale challenges going forward. Observational programs to constrain or discover and characterize the number of truly dark low-mass halos are among the most important, and achievable, goals in this field over then next decade. These efforts will either further verify the $\Lambda$CDM paradigm or demand a substantial revision in our understanding of the nature of dark matter.
991 citations
TL;DR: This new version of micrOMEGAs is a major update which includes a generalization of the Boltzmann equations to accommodate models with asymmetric dark matter or with semi-annihilation and a first approach to a generalizations of the thermodynamics of the Universe in the relic density computation.
922 citations
Perimeter Institute for Theoretical Physics1, Niigata University2, CERN3, University of Connecticut4, Leiden University5, Korea Astronomy and Space Science Institute6, Federico Santa María Technical University7, University of California, Santa Barbara8, University of Maryland, College Park9, Claude Bernard University Lyon 110, University of Lyon11, Northwestern University12, University of Victoria13, University of Manchester14, University of Bonn15, Technische Universität München16, École Polytechnique Fédérale de Lausanne17, Stony Brook University18, Autonomous University of Madrid19, Centre national de la recherche scientifique20, University of Paris21, Moscow Institute of Physics and Technology22, Autonomous University of Barcelona23, University of Copenhagen24, Université libre de Bruxelles25, University of La Serena26, University of Valencia27, Taras Shevchenko National University of Kyiv28, Heidelberg University29, Yonsei University30, Princeton University31, University of Geneva32, Harvard University33, Tomsk State University34, University of Tübingen35, Tomsk Polytechnic University36, University of Washington37, University of Florida38, University of Hamburg39, TRIUMF40, University of Iowa41, University of Grenoble42, International Centre for Theoretical Physics43, Hokkai Gakuen University44, University of Illinois at Urbana–Champaign45, Durham University46, University of Melbourne47, University of Naples Federico II48, York University49, Lawrence Berkeley National Laboratory50, University of California, Berkeley51
TL;DR: It is demonstrated that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.
Abstract: This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, $\tau \to 3\mu $ and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals—scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.
842 citations
TL;DR: A new module of the micrOMEGAs package is presented for the calculation of WIMP–nuclei elastic scattering cross sections relevant for the direct detection of dark matter through its interaction with nuclei in a large detector.
822 citations
TL;DR: The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011 as mentioned in this paper.
Abstract: The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds.
820 citations