Radiative neutrino mass generation from WIMP dark matter
Roberto A. Lineros
备注：
5 pages, 2 figures. To appear in the Proceedings of the XIV International Conference on Topics in Astroparticle and Underground Physics, 7-11 September 2015,Torino, Italy
The minimal seesaw extension of the Standard Model requires two electroweak singlet fermions in order to accommodate the neutrino oscillation parameters at tree level. Here we consider a next to minimal extension where light neutrino masses are generated radiatively by two electroweak fermions: one singlet and one triplet under SU(2). These should be odd under a parity symmetry and their mixing gives rise to a stable weakly interactive massive particle dark matter candidate. For mass in the GeV-TeV range, it reproduces the correct relic density, and provides an observable signal in nuclear recoil direct detection experiments. The fermion triplet component of the dark matter has gauge interactions, making it potentially detectable at present and near future collider experiments.
We make an improved analysis on the flow of neutrinos originating from WIMP annihilations inside the Sun and the Earth. We treat both neutrino interaction and oscillation effects in a consistent framework. Our numerical simulations are performed in an event based setting, which is useful for both theoretical studies and for creating neutrino telescope Monte Carlos. We find that the flow of muon-type neutrinos is enhanced or suppressed depending on the dominant WIMP annihilation channel.
Weakly-interacting massive particles (WIMPs) annihilating in the center of the Sun or the Earth may give rise to energetic neutrinos which might be discovered by astronomical neutrino detectors. The angular distribution of the neutrino-induced muons is considered in detail via Monte Carlo simulations. It is shown that large underground Čerenkov neutrino telescopes might be able to extract the WIMP mass from the width of the muon angular distribution.
The effect of the higher-energy 2nd resonance and the associated adiabatic-to-nonadiabatic transition on neutrino propagation in solar matter is presented. For WIMP-annihilation neutrinos injected with energies in the "sweet region" between 300 MeV and 10 GeV at the Sun's center, a significant and revealing dependence on the neutrino mass hierarchy and the mixing angle theta_13 down to 0.5 degrees is found in the flavor ratios arriving at Earth. In addition, the amplification of flavor ratios in the sweet region allows a better discrimination among possible annihilation modes of the solar dark…
Accumulation and annihilation of weakly interacting massive particles (WIMPs) in the earth and the sun may be observed by the resulting neutrino signal. We demonstrate that, for certain parts of the SUSY parameter space, present and future neutrino telescopes can expect a higher rate of events due to tau-neutrinos than of events due to muon-neutrinos. We show how $ν_τ\leftrightarrowν_μ$ oscillations, and in the case of the sun also scattering, absorption and regeneration, modify the signal expectation. We find that most currently proposed neutralino models predict equal or increased muon fluxe…
The scotogenic scenario provides an attractive approach to both Dark Matter and neutrino mass generation, in which the same symmetry that stabilises Dark Matter also ensures the radiative seesaw origin of neutrino mass. However the simplest scenario may suffer from inconsistencies arising from the spontaneous breaking of the underlying $\mathbb{Z}_2$ symmetry. Here we show that the singlet-triplet extension of the simplest model naturally avoids this problem due to the presence of scalar triplets neutral under the $\mathbb{Z}_2$ which affect the evolution of the couplings in the scalar sector.…
Affleck-Dine (AD) mechanism for leptogenesis involves the cosmological evolution of a complex scalar field (AD field) that carries non-zero lepton number. We show how explicit lepton number breaking terms, which involve the AD field needed to implement this scenario combined with fermionic WIMP dark matter, can generate neutrino mass at the one loop level, thus providing a unified framework for solving four major puzzles of the standard model i.e. inflation, baryogenesis, dark matter and neutrino mass. We discuss some phenomenological implications of this model.
Sterile neutrinos coupling only to third-generation fermions are attractive dark matter candidates. In an EFT approach we demonstrate that they can generate the observed relic density without violating constraints from direct and indirect detection. Such an EFT represents a gauged third-generation $B-L$ model, as well as third-generation scalar or vector leptoquarks. LHC measurements naturally distinguish the different underlying models.
We consider the Peccei-Quinn (PQ) mechanism as the one behind the Dirac neutrino masses when these are generated through the $d=5$ effective operator $\bar{L}\tilde{H}N_Rϕ$ at one loop level, with $ϕ$ being a Standard Model singlet scalar. In this setup, the PQ symmetry guarantees that the one-loop realization of such an effective operator gives the leading contribution to the Dirac neutrino masses by forbidding the contributions arising from its tree level realizations. All the mediators in the one-loop neutrino mass diagrams can be stabilized by a remnant $Z_N$ symmetry from the PQ symmetry …
The minimal seesaw extension of the Standard SU(3) x SU(2) x U(1) Model requires two electroweak singlet fermions in order to accommodate the neutrino oscillation parameters at tree level. Here we consider a next to minimal extension where light neutrino masses are generated radiatively by two electroweak fermions: one singlet and one triplet under SU(2). These should be odd under a parity symmetry and their mixing gives rise to a stable weakly interactive massive particle (WIMP) dark matter candidate. For mass in the GeV-TeV range, it reproduces the correct relic density, and provides an obse…
Weakly interacting massive particles (WIMPs) can be captured by the Sun and annihilate in the core, which may result in production of kaons that can decay at rest into monoenergetic 236 MeV neutrinos. Several studies of detection of these neutrinos at DUNE have been carried out. It has been shown that if the WIMP mass is below 4 GeV, then they will evaporate prior to annihilation, suppressing the signal. Since Jupiter has a cooler core, WIMPs with masses in the 1-4 GeV range will not evaporate and can thus annihilate into monoenergetic neutrinos. We calculate the flux of these neutrinos near t…
Bremsstrahlung of $W$ and $Z$ gauge bosons, or photons, can be an important dark matter annihilation channel. In many popular models in which the annihilation to a pair of light fermions is helicity suppressed, these bremsstrahlung processes can lift the suppression and thus become the dominant annihilation channels. The resulting dark matter annihilation products contain a large, energetic, neutrino component. We consider solar WIMP annihilation in the case where electroweak bremsstrahlung dominates, and calculate the resulting neutrino spectra. The flux consists of primary neutrinos produced…
Annihilation of dark matter particles accumulated in the Sun would produce a flux of high-energy neutrinos whose prospects of detection in neutrino telescopes and detectors have been extensively discussed in the literature. However, for annihilations into Standard Model particles, there would also be a flux of neutrinos in the MeV range from the decays at rest of muons and positively charged pions. These low-energy neutrinos have never been considered before and they open the possibility to also constrain dark matter annihilation in the Sun into e+e-, mu+mu- or light quarks. Here we perform a …
We studied the ionization of hydrogen by scattering of neutrino magnetic moment, relativistic muon, and weakly-interacting massive particle with a QED-like interaction. Analytic results were obtained and compared with several approximation schemes often used in atomic physics. As current searches for neutrino magnetic moment and dark matter have lowered the detector threshold down to the sub-keV regime, we tried to deduce from this simple case study the influence of atomic structure on the the cross sections and the applicabilities of various approximations. The general features being found wi…
We propose a mechanism for baryogenesis from particle decays or annihilations that can work at the TeV scale. Some heavy particles annihilate or decay into a heavy sterile neutrino N (with M > 0.5 TeV) and a "light" one ν(with m << 100 GeV), generating an asymmetry among the two helicity degrees of freedom of ν. This asymmetry is partially transferred to Standard Model leptons via fast Yukawa interactions and reprocessed into a baryon asymmetry by the electroweak sphalerons. We illustrate this mechanism in a WIMPy baryogenesis model where the helicity asymmetry is generated in the annihilation…
The GENIUS proposal is described and some of it's physics potential is outlined. Also in the light of the contradictive results from the DAMA and CDMS experiments the Genius TF, a new experimental setup is proposed. The Genius TF could probe the DAMA evidence region using the WIMP nucleus recoil signal and WIMP annual modulation signature simultaneously. Besides that it can prove the long term feasibility of the detector technique to be implemented into the GENIUS setup and will in this sense be a first step towards the realization of the GENIUS experiment.
We reconsider the discovery limit of multi-ton direct detection dark matter experiments in the light of recent measurements of the coherent elastic neutrino-nucleus scattering process. Assuming the cross section to be a parameter entirely determined by data, rather than using its Standard Model prediction, we use the COHERENT CsI and LAr data sets to determine WIMP discovery limits. Being based on a data-driven approach, the results are thus free from theoretical assumptions and fall within the WIMP mass regions where XENONnT and DARWIN have best expected sensitivities. We further determine th…
The search for weakly interacting massive particles (WIMPs) by direct detection faces an encroaching background due to coherent neutrino-nucleus scattering. For a given WIMP mass the cross section at which neutrinos constitute a dominant background is dependent on the uncertainty on the flux of each neutrino source from either the Sun, supernovae or atmospheric cosmic ray collisions. However there are also considerable uncertainties with regard to the astrophysical ingredients to the predicted WIMP signal. Uncertainties in the velocity of the Sun with respect to the Milky Way dark matter halo,…
By insisting on naturalness in both the electroweak and QCD sectors of the MSSM, the portrait for dark matter production is seriously modified from the usual WIMP miracle picture. In SUSY models with radiatively-driven naturalness (radiative natural SUSY or RNS) which include a DFSZ-like solution to the strong CP and SUSY mu problems, dark matter is expected to be an admixture of both axions and higgsino-like WIMPs. The WIMP/axion abundance calculation requires simultaneous solution of a set of coupled Boltzmann equations which describe quasi-stable axinos and saxions. In most of parameter spa…
Weakly Interacting Massive Particles (WIMPs) are one of the main candidates for the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effect…
We assess the prospects for indirect detection of Weakly Interacting Massive Particles using a large Liquid Argon TPC detector. Signal events will consist of energetic electron (anti)neutrinos coming from the decay of $τ$ leptons and $b$ quarks produced in WIMP annihilation in the core of the Sun. Background contamination from atmospheric neutrinos is expected to be low, thanks to the superb angular resolution and particle identification capabilities provided by the considered experimental set-up. We evaluate the event rates predicted for an annihilating WIMP as a function of its elastic scatt…
Due to its highly suppressed cross section (fermionic) dark matter interacting with the Standard Model via pseudoscalar mediators is expected to be essentially unobservable in direct detection experiments. We consider both a simplified model and a more realistic model based on an extended two Higgs doublet model and compute the leading one-loop contribution to the effective dark matter- nucleon interaction. This higher order correction dominates the scattering rate completely and can naturally, i.e. for couplings of order one, lead to a direct detection cross section in the vicinity of the neu…
If the dark matter of the Universe is constituted by weakly interacting massive particles (WIMP), they would accumulate in the core of astrophysical objects as the Sun and annihilate into particles of the Standard Model. High-energy neutrinos would be produced in the annihilations, both directly and via the subsequent decay of leptons, quarks and bosons. While Cherenkov neutrino detectors/telescopes can only count the number of neutrinos above some threshold energy, we study how, by exploiting their energy resolution, large magnetized iron calorimeter and, possibly, liquid argon and totally ac…
We consider the neutrino (and antineutrino) flavors arriving at Earth for neutrinos produced in the annihilation of weakly interacting massive particles (WIMPs) in the Sun's core. Solar-matter effects on the flavor propagation of the resulting $\agt$ GeV neutrinos are studied analytically within a density-matrix formalism. Matter effects, including mass-state level-crossings, influence the flavor fluxes considerably. The exposition herein is somewhat pedagogical, in that it starts with adiabatic evolution of single flavors from the Sun's center, with $θ_{13}$ set to zero, and progresses to ful…
With positive signals from multiple direct detection experiments it will, in principle, be possible to measure the mass and cross sections of weakly-interacting massive particle (WIMP) dark matter. Recent work has shown that, with a polynomial parameterisation of the WIMP speed distribution, it is possible to make an unbiased measurement of the WIMP mass, without making any astrophysical assumptions. However, direct detection experiments are not sensitive to low-speed WIMPs and, therefore, any model-independent approach will lead to a bias in the cross section. This problem can be solved with …
Weakly interacting massive particles (WIMPs) can be gravitationally captured by the Sun and trapped in its core. The annihilation of those WIMPs into Standard Model particles produces a spectrum of neutrinos whose energy distribution is related to the dark matter mass. In this work, we present the theoretical framework for relating an observed neutrino flux to the WIMP-nucleon cross section and summarize a previous solar WIMP search carried out by IceCube. We then outline an ongoing updated solar WIMP search, focusing on improvements over the previous search.
Nonsupersymmetric minimal SU(5) with Higgs representations ${24}_H$ and $5_H$ and standard fermions in ${\bar 5}_F\oplus {10}_F$ is well known for its failure in unification of gauge couplings and lack of predicting neutrino masses. Like standard model, it is also affected by the instability of the Higgs scalar potential. We note that extending the Higgs sector by ${75}_H$ and ${15}_H$ not only leads to the popular type-II seesaw ansatz for neutrino masses with a lower bound on the triplet mass $M_Δ > 2\times 10^9$ GeV, but also achieves precision unification of gauge couplings without prolife…
We propose a "scotogenic" mechanism relating small neutrino mass and cosmological dark matter. Neutrinos are Dirac fermions with masses arising only in two--loop order through the sector responsible for dark matter. Two triality symmetries ensure both dark matter stability and strict lepton number conservation at higher orders. A global spontaneously broken U(1) symmetry leads to a physical $Diracon$ that induces invisible Higgs decays which add up to the Higgs to dark matter mode. This enhances sensitivities to spin-independent WIMP dark matter search below $m_h/2$.
According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if th…
We point out that when the decay of one electroweak scale super-WIMP state to another occurs at second order in a super-weak coupling constant, this can naturally lead to decay lifetimes that are much larger than the age of the Universe, and create observable consequences for the indirect detection of dark matter. We demonstrate this in a supersymmetric model with Dirac neutrinos, where the right-handed scalar neutrinos are the lightest and next-to-lightest supersymmetric partners. We show that this model produces a super-WIMP decay rate scaling as m_nu^4/(weak scale)^3, and may significantly …
This work presents indirect searches for dark matter (DM) as WIMPs (Weakly Interacting Massive Particles) using neutrino data recorded by the Super-Kamiokande detector from 1996 to 2014. The results of the search for WIMP-induced neutrinos from the Sun and the Milky Way are discussed. We looked for an excess of neutrinos from the Sun/Milky Way direction compared to the expected atmospheric neutrino background. Event samples including both electron and muon neutrinos covering a wide range of neutrino energies (GeV to TeV) were used, with sensitivity to WIMP masses down to tens of GeV. Various W…
Dark matter particles captured by the Sun through scattering may annihilate and produce neutrinos, which escape. Current searches are for the few high-energy neutrinos produced in the prompt decays of some final states. We show that interactions in the solar medium lead to a large number of pions for nearly all final states. Positive pions and muons decay at rest, producing low-energy neutrinos with known spectra, including nuebar through neutrino mixing. We demonstrate that Super-Kamiokande can thereby provide a new probe of the spin-dependent WIMP-proton cross section. Compared to other meth…
In this work we show that from the spectrum of particles of a 3-3-1 gauge model with heavy sterile neutrinos we can have up to three Cold Dark Matter candidates as WIMPs. We obtain their relic abundance and analyze their compatibility with recent direct detection experiments, exploring the possibility of explaining the two events reported by CDMS-II. An interesting outcome of this 3-3-1 model, concerning direct detection of two WIMPs in the model, is a strong bound on the symmetry breaking scale, which imposes it to be above 3 TeV.
We investigate the signatures of neutrinos produced in the annihilation of WIMP dark matter in the Earth, the Sun and at the Galactic centre within the framework of the Inert Doublet Model and extensions. We consider a dark matter candidate, that we take to be one of the neutral components of an extra Higgs doublet, in three distinct mass ranges, which have all been shown previously to be consistent with both WMAP abundance and direct detection experiments exclusion limits. Specifically, we consider a light WIMP with mass between 4 and 8 GeV (low), a WIMP with mass around 60-70 GeV (middle) an…
Weakly interacting massive particles (WIMPs) are a viable candidate for the relic abundance of dark matter (DM) produced in the early universe. So far WIMPs have eluded direct detection through interactions with baryonic matter. Neutrino emission from accumulated WIMP annihilations in the solar core has been proposed as a signature of DM, but has not yet been detected. These null results may be due to small scale DM density fluctuations in the halo with the density of our local region being lower than the average (around 0.3 GeV/cm^3 ). However, the accumulated neutrino signal from WIMP annihi…
(Abridged) In the presence of a light WIMP (< 30 MeV), there are degeneracies among the nature of the WIMP, its couplings to standard model particles, its mass m_chi, and the number of equivalent neutrinos beyond the standard model, Delta N_nu. These degeneracies cannot be broken by the CMB constraint on the effective number of neutrinos, N_eff. However, big bang nucleosynthesis (BBN) is affected by a light WIMP and equivalent neutrinos, so the combination of BBN and CMB can break some of the degeneracies. Here, BBN predictions for abundances in the presence of a light WIMP and equivalent neut…
Recently, the DAMA/LIBRA collaboration has repeated and reinforced their claim to have detected an annual modulation in their signal rate, and have interpreted this observation as evidence for dark-matter particles at the 8.2 sigma confidence level. Furthermore, it has also been noted that the effects of channeling may enable a WIMP that scatters elastically via spin-independent interactions from nuclei to produce the signal observed by DAMA/LIBRA without exceeding the limits placed by CDMS, XENON, CRESST, CoGeNT and other direct-detection experiments. To accommodate this signal, however, the …
The dense energy deposition from a low-energy nuclear recoil produces, via the thermoacoustic effect, a brief yet intense pressure pulse that can be used for WIMP or neutrino detection in some fiber-optic devices sensitive to acoustooptic disturbances. Several possible detection schemes are described: all of them are inspired by modern fiber-optic sensor technologies and share common characteristics of low-cost and expected insensitivity to minimum-ionizing backgrounds.
Upper limits on the spin-independent (SI) as well as spin-dependent (SD) elastic scattering cross sections of WIMPs with protons, imposed by the Super-Kamiokande (S-K) upper limit on the neutrino flux from WIMP annihilation in the Sun, and their compatibility with the "DAMA-compatible" regions of the WIMP parameter space within which the annual modulation signal observed by the DAMA/LIBRA experiment is compatible with the null results of other direct detection experiments, are studied within the frame work of a self-consistent model of the finite-size dark matter (DM) halo of the Galaxy, the p…
Semi-analytic treatments of the evolution of orbits of weakly interacting massive particles (WIMPs) in the solar system suggest that the WIMPs bound to the solar system may enhance the direct detection rate relative to that of the unbound population by up to a factor of order unity, and boost the flux of neutrinos from WIMP annihilation in the Earth by up to two orders of magnitude. To test these important but uncertain results, we perform a suite of numerical orbit integrations to explore the properties of the bound WIMP population as a function of the WIMP mass and the scattering cross secti…
Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；University of California, Berkeley（加州大学伯克利分校）；INFN, Sezione di Firenze（意大利国家核物理研究所佛罗伦萨分部）；LAPTh, Université Savoie Mont-Blanc et CNRS（萨瓦蒙布朗大学与法国国家科学研究中心拉普特实验室）
We combine experimental constraints from direct detection searches and from neutrino telescopes looking for WIMP annihilations in the Sun to derive halo-independent bounds on each of the 28 WIMP-proton and WIMP-neutron couplings of the effective non-relativistic Hamiltonian that drives the scattering process off nuclei of a WIMP of spin 1/2. The method assumes that the velocity distribution is normalized to one and homogeneous at the the solar system scale, as well as equilibrium between WIMP capture and annihilation in the Sun, and requires to fix the WIMP annihilation channels (we assume $b\…
We study the capture of WIMP dark matter by the Sun in the non-relativistic effective theory of dark matter self-interactions. The aim is to assess the impact of self-interactions on the expected neutrino flux from the annihilation of WIMPs trapped in the Sun in a model independent manner. We consider all non-relativistic Galilean invariant self-interaction operators that can arise from the exchange of a heavy particle of spin less than or equal to 1 for WIMPs of spin equal to 0, 1/2 and 1. We show that for interaction operators depending at most linearly on the momentum transfer, the WIMP-ind…
We study a discrete flavour symmetric scenario for neutrino mass and dark matter under the circumstances where such global discrete symmetries can be explicitly broken at Planck scale, possibly by gravitational effects. Such explicit breaking of discrete symmetries mimic as Planck suppressed operators in the model which can have non-trivial consequences for neutrino and dark matter sectors. In particular, we study a flavour symmetric model which, at renormalisable level, gives rise to tri-bimaximal type neutrino mixing with vanishing reactor mixing angle $θ_{13}=0$, a stable inert scalar doubl…
Weakly interacting massive particles (WIMPs) may be indirectly detected by observation of upward muons induced by energetic neutrinos from annihilation of WIMPs that have accumulated in the Sun and/or Earth. Energetic muon neutrinos come from the decays of $τ$ leptons, $c$, $b$, and $t$ quarks, gauge bosons, and Higgs bosons produced by WIMP annihilation. We provide analytic expressions, suitable for computing the flux of upward muons, for the neutrino energy spectra from decays of all these particles in the center of the Sun and Earth. These analytic expressions should obviate the need for Mo…
We present updated results of the Baksan Underground Scintillator Telescope in search for a signal from dark matter particles annihilating in the center of the Sun. Based on the performance of the Baksan telescope measuring upward through-going muons with energy larger 1 GeV, we confirm the absence of observable excess in arrival directions towards the Sun relatively the expectations from neutrinos of atmospheric origin for 24.12 years of live time. We conclude that the 90% C.L. upper limits on elastic scattering cross sections of dark matter WIMP (Weakly Interactive Massive Particle) off prot…
In experiments for direct dark matter searches, neutrinos coherently scattering off nuclei can produce similar events as Weakly Interacting Massive Particles (WIMPs). The calculated count rate for solar neutrinos in such experiments is a few events per ton-year. This count rate strongly depends on the nuclear recoil energy threshold achieved in the experiments for the WIMP search. We show that solar neutrinos can be a serious background source for direct dark matter search experiments using Ge, Ar, Xe and CaWO_4 as target materials. To reach sensitivities better than approximatly 10^-10 pb for…
We consider the possibility that a massive fourth family neutrino, predicted by a recently proposed minimal technicolor theory, could be the source of the dark matter in the universe. The model has two techniflavors in the adjoint representation of an SU(2) techicolor gauge group and its consistency requires the existence of a fourth family of leptons. By a suitable hypercharge assignement the techniquarks together with the new leptons look like a conventional fourth standard model family. We show that the new (Majorana) neutrino N can be the dark matter particle if $m_N \sim 100-500$ GeV and …
We calculate the annihilation rate of weakly interacting massive particles (WIMPs) in the Sun as a function of their mass and elastic scattering cross section. One byproduct of the annihilation, muon neutrinos, may be observed by the next generation of neutrino telescopes. Previous estimates of the annihilation rate assumed that any WIMPs from the Galactic dark halo that are captured in the Sun by elastic scattering off solar nuclei quickly reach thermal equilibrium in the Sun. We show that the optical depth of the Sun to WIMPs and the gravitational forces from planets both serve to decrease t…
The signals observed at the direct detection experiments DAMA, CoGeNT and CRESST could be explained by light WIMPs with sizeable spin-independent cross sections with nucleons. The capture and subsequent annihilation of such particles in the sun would induce neutrino signals in the GeV range which may be observed at Super-Kamiokande. We determine the rate of upward stopping muons and fully contained events at Super-Kamiokande for various possible WIMP annihilation channels. This allows us to provide strong constraints on the cross section of WIMPs with nucleons. We find that the DAMA and CoGeNT…
Neutrino telescopes are looking to detect neutrinos produced by the annihilation of weakly interacting massive particle (WIMP) dark matter in the sun. The event rate depends on the dark matter density in the sun, which in turn is dictated by the cross section of WIMPs with nucleons. This however is bounded by direct detection experiments. We use the constraints from these experiments to place model-independent upper bounds on the event rates in neutrino telescopes that apply to any elastic dark matter model. Since the spin-independent WIMP-nucleon cross section is much more tightly constrained…
A proposal submitted to the FNAL PAC is described to search for light sub-GeV WIMP dark matter at MiniBooNE. The possibility to steer the beam past the target and into an absorber leads to a significant reduction in neutrino background, allowing for a sensitive search for elastic scattering of WIMPs off nucleons or electrons in the detector. Dark matter models involving a vector mediator can be probed in a parameter region consistent with the required thermal relic density, and which overlaps the region in which these models can resolve the muon g-2 discrepancy. Estimates of signal significanc…
I show that it may be possible to explain the present evidence for a gamma-ray emission from the galactic halo as due to halo WIMP annihilations. Not only the intensity and spatial pattern of the halo emission can be matched but also the relic density of the candidate WIMP can be in the cosmologically interesting domain. After a model-independent analysis to learn about the properties of a suitable candidate, I present a working model: a sterile neutrino in a model with an extended Higgs sector. Two examples indicate the existence of an interesting region in the model parameter space where pre…
