Neutrino and dark matter physics with sub-keV germanium detectors

Germanium detectors with sub-keV sensitivities open a window to study neutrino physics to search for light weakly interacting massive particle (WIMP) dark matter. We summarize the recent results on spin-independent couplings of light WIMPs from the TEXONO experiment at the Kuo-Sheng Reactor Neutrino Laboratory. Highlights of the physics motivation, our R&D programme, as well as the status and plans are presented.     

Galactic searches for dark matter

For nearly a century, more mass has been measured in galaxies than is contained in the luminous stars and gas. Through continual advances in observations and theory, it has become clear that the dark matter in galaxies is not comprised of known astronomical objects or baryonic matter, and that identification of it is certain to reveal a profound connection between astrophysics, cosmology, and fundamental physics. The best explanation for dark matter is that it is in the form of a yet undiscovered particle of nature, with experiments now gaining sensitivity to the most well-motivated particle dark matter candidates. In this article, I review measurements of dark matter in the Milky Way and its satellite galaxies and the status of Galactic searches for particle dark matter using a combination of terrestrial and space-based astroparticle detectors, and large scale astronomical surveys. I review the limits on the dark matter annihilation and scattering cross sections that can be extracted from both astroparticle experiments and astronomical observations, and explore the theoretical implications of these limits. I discuss methods to measure the properties of particle dark matter using future experiments, and conclude by highlighting the exciting potential for dark matter searches during the next decade, and beyond.     

Neutrino mass models and dark matter

We discuss a possibility to relate neutrino mass to dark matter. If we suppose that neutrino masses are generated through a radiative seesaw mechanism, dark matter may be identified with a stable field which is relevant to the neutrino mass generation. The model is severely constrained by lepton flavor violating processes. We show some solutions to this constraint.     

Indirect searches for dark matter

The current status of indirect searches for dark matter has been reviewed in a schematic way here. The main relevant experimental results of the recent years have been listed and the excitements and disappointments that their phenomenological interpretations in terms of almost-standard annihilating dark matter have brought along have been discussed. The main sources of uncertainties that affect this kind of searches are also listed. [Report number: Saclay T11/206, CERN-PH-TH/2011-257, extended version in arXiv:1202.1454], [Prepared for the Proceedings of Lepton?CPhoton 2011, Mumbai, India, 22?C27 Aug. 2011].     

Neutrino sector impacts SUSY dark matter

Motivated by the fact that neutrinos are massive, we study the effect of neutrino Yukawa couplings on neutralino dark matter observables within the framework of a supersymmetric seesaw. We find that neutrino couplings significantly affect the neutralino relic density in regions of parameter space where soft SUSY-breaking slepton masses and/or trilinear couplings are large. Depending on the size of the couplings, the neutralino relic density spans over an order of magnitude in the A-funnel, focus point and stop-coannihilation regions of mSUGRA. We also show that dark matter detection rates can be modified by up to several orders of magnitude.     

Indirect searches for dark matter with AMS-02

AMS-02 is a multi-purpose spectrometer with superconducting magnet, and is designed for 3 years of data taking aboard the International Space Station. Its high performance regarding particle identification and energy measurement will allow performing indirect searches for dark matter (DM) in different channels simultaneously: gamma rays, positrons and antiprotons. AMS-02 sensitivity to those signals are presented and – provided the positron excess is due to DM signal – it is shown that it allows to probe new physics models in detail. Its high sensitivity could even be a unique opportunity to reach the Majorana nature of the DM particle through final state polarization effects. PACS  95.35.+d; 95.55.Vj     

Recent developments in dark matter searches

A brief review is first given of the forms of dark matter that are hypothesized, and a summary of the basic observational evidence for dark matter is provided. Then a summary of recent results from indirect and direct detection dark matter search experiments is given. Some discussion is also done of MOND theories along with recent analysis of galaxy surface density data that provides some support for such theories.     

Direct detection searches for WIMP dark matter

A very active hunt is underway to discover the composition of dark matter in the universe. A large effort is devoted to the direct detection of dark matter through interactions with detectors in the laboratory. In this paper, we give an overview of the dark matter problem, discuss some of the design considerations taken in direct detection experiments, and describe some of the current efforts to discover Weakly Interacting Massive Particles (WIMPs), a well-motivated class of candidates for dark matter.     

Testing ATLAS diboson excess with dark matter searches at LHC

Journal of High Energy Physics - Recently an orthogonal basis of $$ {mathcal{W}}_N $$ -algebra (AFLT basis) labeled by N-tuple Young diagrams was found in the context of 4D/2D duality. Recursion...     

Neutrino interactions in dense stellar matter

Weak-interaction rates play an important role in the birth of neutron stars in core collapse supernova and their subsequent thermal evolution. In this paper, I highlight the role of strong interactions and phase transitions in calculations of neutrino scattering and emission rates in dense stellar matter.Received: 1 November 2002, Published online: 15 July 2003PACS: 13.15.+g Neutrino interactions - 13.20.-v Leptonic and semileptonic decays of mesons - 26.50.+x Nuclear physics aspects of novae, supernovae, and other explosive environments - 26.60.+c Nuclear matter aspects of neutron starsPresent address: Los Alamos National Laboratory, P.O. Box 1663, MS B283, Los Alamos, NM 87545, USA     

Low-energy neutrino and dark matter physics with sub-keV germanium detectors

The TEXONO-CDEX Collaboration (Taiwan experiment on neutrino?CChina dark matter experiment) explores high-purity germanium (HPGe) detection technology to develop a sub-keV threshold detector for pursuing studies on low mass weakly interacting massive particles (WIMPs), properties of neutrino and the possibilities of neutrino-nucleus coherent scattering observation. This article will introduce the facilities of newly established China Jing-Ping Underground Laboratory (CJPL), preliminary result of cosmic ray background studies at CJPL, the dark matter studies pursued at Kuo-Sheng Neutrino Laboratory (KSNL) and research efforts to accomplish our physics goals.     

Neutrino masses, dark matter and the mysterious early quasars

The lightest right-handed or sterile neutrino, that is embedded in a renormalizable seesaw-like extension of the standard model, with a mass and a tiny mixing θ∼10^−6.5 to one of the left-handed active neutrinos, is an attractive quasi-stable dark matter particle candidate. This sterile neutrino is produced in the early universe with the dark matter abundance required by WMAP. It is quasi-stable, decaying in about 10¹⁹ years into two neutrinos and an antineutrino, and it may be observed directly through its subdominant radiative decay into an active neutrino and a photon in about 10²¹ years. In contrast to the galaxies, that are known to form hierarchically, the supermassive black holes are formed anti-hierarchically, i.e. the most massive quasars first, and the least massive active galactic nuclei last. Here we argue that the anti-hierarchical formation of the supermassive black holes may be due to the possibility that both, the quasars and active galactic nuclei, may originate from supermassive degenerate neutrino balls that are swallowed up by stellar-mass black holes, produced by supernova explosions of massive stars at the centers of the neutrino balls.     

A review of indirect searches for particle dark matter

The indirect detection of dark matter annihilation and decay using observations of photons, charged cosmic rays and neutrinos offers a promising means of identifying the particle nature of this elusive component of the universe. The last decade has seen substantial advances in observational data-sets, complemented by new insights from numerical simulations, which together have enabled for the first time strong constraints on dark matter particle models, and have revealed several intriguing hints of possible signals. This review provides an introduction to indirect detection methods and an overview of recent results in the field.     

Neutrino physics with cryogenic detectors

The recent results on neutrino oscillations and the consequent need to measure the value of the neutrino mass are briefly discussed. The operating principle of cryogenic detectors working at low temperatures, where the small heat capacity allows one to record and measure the temperature increase due to the tiny energy lost by a particle in form of heat is described. An application of these detectors is the measurement, or at least an upper constraint, of the neutrino mass in β decay. This approach is complementary and can, in the future, be competitive with experiments based on the spectrometric measurement of the electron energy. The search for neutrinoless double beta decay could reach a better sensitivity on the mass if a neutrino is a Majorana particle. A large cryogenic detector, named CUORICINO, on neutrinoless double beta decay (DBD) of ¹³⁰Te already yields the best constraint on the absolute value of the Majorana neutrino mass. A much larger detector, named CUORE, for Cryogenic Underground Observatory for Rare Events, is currently under construction. With its active mass of 750 kg of natural TeO₂ it aims to reach the sensitivity in the determination of the Majorana neutrino mass suggested by the results of neutrino oscillation under the inverse hierarchy hypothesis. The problem is closely connected with what I call “the second mystery of Ettore Majorana” who suggested a particle that would violate the lepton number.     

Indirect dark matter searches in our Galaxy in comparison with FERMI data

The first 2-year data on the diffuse gamma rays from the FERMI satellite are analyzed and compared with expectations from dark matter annihilation. Although the published results at intermediate latitudes do not confirm the EGRET GeV excess, the data towards the Galactic center are hard to explain with standard propagation models. Redoing a template shape fit to the data in about 900 independent sky directions reveals that the FERMI data are best described by including a DMA contribution from an NFW DM profile with a ringlike DM substructure, as required to describe the new precise data on the gas flaring and rotation curve.     

Scalar quintuplet minimal dark matter with Yukawa interactions:perturbative up to the Planck scale

We confront the perturbativity problem in the real scalar quintuplet minimal dark matter model. In the original model, the quintuplet quartic self-coupling inevitably hits a Landau pole at a scale ～10~(14) GeV, far below the Planck scale. In order to push up this Landau pole scale, we extend the model with a fermionic quintuplet and three fermionic singlets which couple to the scalar quintuplet via Yukawa interactions. Involving such Yukawa interactions at a scale ～10~(10) GeV can not only keep all couplings perturbative up to the Planck scale, but can also explain the smallness of neutrino masses via the type-I seesaw mechanism. Furthermore, we identify the parameter regions favored by the condition that perturbativity and vacuum stability are both maintained up to the Planck scale.     

Neutrino indirect detection of neutralino dark matter in the CMSSM

We study potential signals of neutralino dark matter indirect detection by neutrino telescopes in a wide range of CMSSM parameters. We also compare with direct detection potential signals taking into account in both cases present and future experiment sensitivities. Only models with neutralino annihilation into gauge bosons can satisfy cosmological constraints and current neutrino indirect detection sensitivities. For both direct and indirect detection, only next generation experiments will be able to really test this kind of models. Received: 12 April 2002 / Revised version: 16 July 2002 / Published online: 18 October 2002 RID="a" ID="a" e-mail: bertin@cppm.in2p3.fr RID="b" ID="b" e-mail: nezri@in2p3.fr RID="c" ID="c" e-mail: orloff@in2p3.fr