Author
Sebastian Kempf
Other affiliations: Karlsruhe Institute of Technology
Bio: Sebastian Kempf is an academic researcher from Heidelberg University. The author has contributed to research in topics: Detector & Multiplexer. The author has an hindex of 18, co-authored 70 publications receiving 1361 citations. Previous affiliations of Sebastian Kempf include Karlsruhe Institute of Technology.
Topics: Detector, Multiplexer, Electron capture, Calorimeter, Neutrino
Papers
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Jamia Millia Islamia1, Hanoi University of Science2, Vietnam Academy of Science and Technology3, 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, Moscow Institute of Physics and Technology29, Russian Academy of Sciences30, 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
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.
163 citations
30 Dec 2009
TL;DR: Metallic magnetic calorimeters (MMCs) as discussed by the authors are calorimetric particle detectors, typically operated at temperatures below 100 mK, that make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc‐SQUID.
Abstract: Metallic magnetic calorimeters (MMC) are calorimetric particle detectors, typically operated at temperatures below 100 mK, that make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc‐SQUID. During the last years a growing number of groups has started to develop MMC for a wide variety of applications, ranging from alpha‐, beta‐ and gamma‐spectrometry over the spatially resolved detection of accelerated molecule fragments to arrays of high resolution x‐ray detectors. For x‐rays with energies up to 6 keV an energy resolution of 2.7 eV (FWHM) has been demonstrated and we expect that this can be pushed below 1 eV with the next generation of devices. We give an introduction to the physics of MMCs and summarize the presently used readout schemes as well as the typically observed noise contributions and their impact on the energy resolution. We discuss general design considerations, the micro‐fabrication of MMCs and the performance of micro‐fabricated devices. In this field large progress has been achieved in the last years and the thermodynamic properties of most materials approach bulk values allowing for optimal and predictable performance.
110 citations
Heidelberg University1, Max Planck Society2, University of Mainz3, CERN4, Dresden University of Technology5, University of Bern6, Paul Scherrer Institute7, University of Tübingen8, Goethe University Frankfurt9, Saha Institute of Nuclear Physics10, Indian Institute of Technology Roorkee11, Saint Petersburg State University12, Petersburg Nuclear Physics Institute13, Humboldt University of Berlin14, Karlsruhe Institute of Technology15, Comenius University in Bratislava16
TL;DR: The ECHo-1K experiment as mentioned in this paper was designed to achieve sub-eV sensitivity on the electron neutrino mass by means of the analysis of the calorimetrically measured electron capture spectrum of the nuclide$^{163}$Ho.
Abstract: Neutrinos, and in particular their tiny but non-vanishing masses, can be considered one of the doors towards physics beyond the Standard Model. Precision measurements of the kinematics of weak interactions, in particular of the$^{3}$H β-decay and the$^{163}$Ho electron capture (EC), represent the only model independent approach to determine the absolute scale of neutrino masses. The electron capture in$^{163}$Ho experiment, ECHo, is designed to reach sub-eV sensitivity on the electron neutrino mass by means of the analysis of the calorimetrically measured electron capture spectrum of the nuclide$^{163}$Ho. The maximum energy available for this decay, about 2.8 keV, constrains the type of detectors that can be used. Arrays of low temperature metallic magnetic calorimeters (MMCs) are being developed to measure the$^{163}$Ho EC spectrum with energy resolution below 3 eV FWHM and with a time resolution below 1 μs. To achieve the sub-eV sensitivity on the electron neutrino mass, together with the detector optimization, the availability of large ultra-pure$^{163}$Ho samples, the identification and suppression of background sources as well as the precise parametrization of the$^{163}$Ho EC spectrum are of utmost importance. The high-energy resolution$^{163}$Ho spectra measured with the first MMC prototypes with ion-implanted$^{163}$Ho set the basis for the ECHo experiment. We describe the conceptual design of ECHo and motivate the strategies we have adopted to carry on the present medium scale experiment, ECHo-1K. In this experiment, the use of 1 kBq$^{163}$Ho will allow to reach a neutrino mass sensitivity below 10 eV/c$^{2}$. We then discuss how the results being achieved in ECHo-1k will guide the design of the next stage of the ECHo experiment, ECHo-1M, where a source of the order of 1 MBq$^{163}$Ho embedded in large MMCs arrays will allow to reach sub-eV sensitivity on the electron neutrino mass.
103 citations
TL;DR: In this paper, the authors present the electron capture experiment ECHo, which aims to investigate the electron neutrino mass in the sub-eV range by means of the analysis of the calorimetrically measured energy spectrum following electron capture.
Abstract: The determination of the absolute scale of the neutrino masses is one of the most challenging present questions in particle physics. The most stringent limit, $$m(\bar{
u }_{\mathrm {e}})< 2$$
eV, was achieved for the electron anti-neutrino mass. Different approaches are followed to reach a sensitivity on neutrino masses in the sub-eV range. Among them, experiments exploring the beta decay or electron capture of suitable nuclides can provide information on the electron neutrino mass value. We present the electron capture $$^{163}$$
Ho experiment ECHo, which aims to investigate the electron neutrino mass in the sub-eV range by means of the analysis of the calorimetrically measured energy spectrum following electron capture in $$^{163}$$
Ho. A high precision and high statistics spectrum will be measured with arrays of metallic magnetic calorimeters. We discuss some of the essential aspects of ECHo to reach the proposed sensitivity: detector optimization and performance, multiplexed readout, $$^{163}$$
Ho source production and purification, as well as a precise theoretical and experimental parameterization of the calorimetric EC spectrum including in particular the value of $$Q_{\mathrm {EC}}$$
. We present preliminary results obtained with a first prototype of single channel detectors as well as a first 64-pixel chip with integrated micro-wave SQUID multiplexer, which will already allow to investigate $$m(
u _{\mathrm {e}})$$
in the eV range.
99 citations
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28,685 citations
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: The dark energy plus cold dark matter (ΛCDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of the Universe and its evolution with time as mentioned in this paper.
Abstract: The dark energy plus cold dark matter (ΛCDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of the Universe and its evolution with time. Yet on length scales smaller than ∼1 Mpc and mass scales smaller than ∼1011M⊙, 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 ΛCDM. 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 ΛCDM: 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 is required to meet these challenges. Other anomalies, including the observed planar and orbital configurations of Local Group satellites and the tight baryonic...
675 citations
TL;DR: In this article, the authors present an overview of scenarios where the observed dark matter (DM) abundance consists of Feebly Interacting Massive Particles (FIMPs), produced nonthermally by the so-called freeze-in mechanism.
Abstract: We present an overview of scenarios where the observed Dark Matter (DM) abundance consists of Feebly Interacting Massive Particles (FIMPs), produced nonthermally by the so-called freeze-in mechanism. In contrast to the usual freeze-out scenario, frozen-in FIMP DM interacts very weakly with the particles in the visible sector and never attained thermal equilibrium with the baryon–photon fluid in the early Universe. Instead of being determined by its annihilation strength, the DM abundance depends on the decay and annihilation strengths of particles in equilibrium with the baryon–photon fluid, as well as couplings in the DM sector. This makes frozen-in DM very difficult but not impossible to test. In this review, we present the freeze-in mechanism and its variations considered in the literature (dark freeze-out and reannihilation), compare them to the standard DM freeze-out scenario, discuss several aspects of model building, and pay particular attention to observational properties and general testability o...
491 citations