We consider a simplest extension of the Standard Model (SM) through the incorporation of a real scalar singlet and an additional discrete $Z_2$ symmetry. The model admits the neutral scalar singlet to be stable and thus, a viable component of dark matter. We explore the parameter space of the model keeping in view the constraints arise from different dark matter direct detection experiments through WIMP-nucleon scattering. First of all, we have utilised the data obtained from CDMS, XENON-10 and XENON-100 collaborations. We further constraint the parameter space from the DAMA collaboration results (both with and without channelling) and CoGeNT collaboration results. Throughout our analysis, the constraint arises due to the observed relic density of dark matter reported by WMAP experiment, is also incorporated. Utilising all those constraints, on the model parameter space, we calculate the event rates and the annual variation of event rates in the context of a Liquid Argon Detector experiment.
In this talk we briefly review the current CDMS/XENON constraints on the neutralino dark matter in three popular supersymmetric models: the minimal (MSSM), the next-to-minimal (NMSSM) and the nearly minimal (nMSSM). The constraints from the dark matter relic density and various collider experiments are also taken into account. The conclusion is that for each model the current CDMS/XENON limits can readily exclude a large part of the parameter space allowed by other constraints and the future SuperCDMS or XENON100 can cover most of the allowed parameter space. The implication for the Higgs sear…
For the milli-charged Dirac dark matter in the Stueckelberg Z' model, we discuss the contributions from the vector couplings of the dark matter with the neutral gauge bosons to the spin-independent scattering cross section in the direct detections. We also compute the effective coupling between the fermionic dark matter particle and the standard model Higgs boson generated through a triangular loop of Z and/or Z' bosons which may contribute to the spin-independent scattering cross section at the quantum level. We show that the latter contribution is consistent with the most recent experimental…
The CDMS-II collaboration has reported 3 events in a Si detector, which are consistent with being nuclear recoils due to scattering of Galactic dark matter particles with a mass of about 8.6 GeV and a cross-section on neutrons of about 2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has supposedly ruled out such particles as dark matter, we find by reanalysing the XENON10 data that this is not the case. Some tension remains however with the upper limit placed by the XENON100 experiment, independently of astrophysical uncertainties concerning the Galactic dark matter distri…
We consider the prospect of lightest neutralino (${\tilde χ}_1^0$) as a dark matter candidate in the light of recent interesting observations from the XENON100 and CDMS-II experiments in minimal supergravity framework with large $\tanβ$ and non-vanishing $A_0$. Within the WMAP satisfied zone, there is a large direct detection reach of lighter ${\tilde χ}_1^0$ in the lighter Higgs boson mediated resonance annihilation domain of the above scenario. It is seen that the heavier Higgs boson plays a dominating role in the ${\tilde χ}_1^0-p$ cross-section in the associated zone of parameter space in …
We re-analyse the implications of the DAMA/NaI experiment for mirror matter-type dark matter, taking into account information from the energy dependence of the DAMA annual modulation signal. This is combined with the null results from the CDMS experiment, leading to fairly well defined allowed regions of parameter space. The allowed regions of parameter space will be probed in the near future by the DAMA/LIBRA, CDMS, and other experiments, which should either exclude or confirm this explanation of the DAMA/NaI annual modulation signal. In particular, we predict that the CDMS experiments should…
We examine the recent CDMS II results in the context of the mirror matter interpretation of the DAMA/NaI experiment.We find that the favoured mirror matter interpretation of the DAMA/NaI experiment -- a $He'/H'$ dominated halo with a small $O'$ component is fully consistent with the null results reported by CDMS II. While the CDMS II experiment is quite sensitive to a heavy $Fe'$ component, and may yet find a positive result, a more decisive test of mirror matter-type dark matter would require a lower threshold experiment using light target elements.
Many experiments seek dark matter by detecting relatively low energy nuclear recoils. Yet since events from ordinary physics with energies in the 1-100 KeV range are commonplace, all claims of signals or their absence hinge on exhaustive calibrations and background rejection. We document many curious and consistent discrepancies between the backgrounds which neutrons can produce versus the picture of neutrons and claims of neutron calibration found in dark matter literature. Much of the actual physics of neutrons is either under-recognized or under-reported, opening up new interpretations of c…
We consider the possibility that the recently reported events at the CDMS-II direct dark matter detection experiment are the result of coherent scattering of supersymmetric neutralinos. In such a scenario we argue that non-universal soft supersymmetry breaking gaugino masses are favored with a resulting lightest neutralino with significant Higgsino and wino components. We discuss the accompanying signals which must be seen at liquid-xenon direct detection experiments and indirect detection experiments if such a supersymmetric interpretation is to be maintained. We illustrate the possible conse…
Previous work has argued that the DAMA annual modulation signal might be due to electron recoils in plasma dark matter models. A specific model assuming mirror dark matter and featuring collisional shielding of a detector due to Earth-bound dark matter was put forward by this author [arXiv:1806.04293]. That explanation predicted a low energy electron recoil signal in the XENON1T experiment. In light of the excess of electron recoils observed in XENON1T, we re-examine that model's predictions for both DAMA and XENON1T.
We examine data from the DAMA, CoGeNT, CRESST-II and CDMS/Si direct detection experiments in the context of multi-component hidden sector dark matter. The models considered feature a hidden sector with two or more stable particles charged under an unbroken $U(1)'$ gauge interaction. The new gauge field can interact with the standard $U(1)_Y$ via renormalizable kinetic mixing, leading to Rutherford-type elastic scattering of the dark matter particles off ordinary nuclei. We consider the simplest generic model of this type, with a hidden sector composed of two stable particles, $F_1$ and $F_2$. …
Although observations made with the CoGeNT and CDMS experiments have been interpreted as possible signals of low-mass (~7-10 GeV) dark matter particles, constraints from the XENON100 collaboration appear to be incompatible with this hypothesis, at least at face value. In this paper, we revisit XENON100's constraint on dark matter in this mass range, and consider how various uncertainties and assumptions made might alter this conclusion. We also note that while XENON100's two nuclear recoil candidates each exhibit very low ratios of ionization-to-scintillation signals, making them difficult to …
We show that mostly right-handed Dirac sneutrino is a viable supersymmetric light dark matter candidate. While the Dirac sneutrino scattering with nuclei is dominantly through the $Z$ boson exchange and is stringently constrained by the invisible decay width of $Z$ boson, it is possible to realize a large enough cross section with nucleon to account for possible signals observed at direct dark matter searches such as CDMS II-Si or CoGeNT. Even if the XENON100 limit is taken into account, a small part of signal region for CDMS II-Si events remains outside the excluded region by XENON100.
The DAMA annual modulation signature, interpreted as evidence for a spin-independent WIMP coupling, seems in conflict with null results from CDMS. However, in models of ``inelastic dark matter'', the experiments are compatible. Inelastic dark matter can arise in supersymmetric theories as the real component of a sneutrino mixed with a singlet scalar. In contrast with ordinary sneutrino dark matter, such particles can satisfy all experimental constraints while giving the appropriate relic abundance. We discuss the modifications to the signal seen at DAMA, in particular noting the strong suppres…
We point out that mirror dark matter predicts low energy ($E_R \stackrel{<}{\sim} 2$ keV) electron recoils from mirror electron scattering as well as nuclear recoils from mirror ion scattering. The former effect is examined and applied to the recently released low energy electron recoil data from the CDMS collaboration. We speculate that the sharp rise in electron recoils seen in CDMS below 2 keV might be due to mirror electron scattering and show that the parameters suggested by the data are roughly consistent with the mirror dark matter explanation of the annual modulation signal observed in…
We show that exothermic isospin-violating dark matter (IVDM) can make the results of the latest CDMS-Si experiment consistent with recent null experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate exothermic dark matter or isospin-violating dark matter cannot fully ameliorate the tensions among these experiments; the tension disappears only if exothermic scattering is combined with an isospin-violating effect of f_n/f_p=-0.7. For such exothermic IVDM to exist, at least a new vector gauge boson…
We investigate the constraints of dark matter search experiments on the different candidates emerging from the minimal quasi-conformal strong coupling theory with fermions in the adjoint representation. For one candidate, the current limits of CDMS exclude a tiny window of masses around 120 GeV. We also investigate under what circumstances the newly proposed candidate composed of a -2 negatively charged particle and a $^4He^{+2}$ can explain the discrepancy between the results of the CDMS and DAMA experiments. We found that this type of dark matter should give negative results in CDMS, while i…
Mirror dark matter offers a framework to explain the existing dark matter direct detection experiments, including the impressive DAMA annual modulation signal. Here we examine the implications of mirror dark matter for experiments like CDMSII/Ge and XENON10 which feature higher recoil energy threshold than the DAMA NaI experiments. We show that the two events seen in the CDMSII/Ge experiment are consistent with the interactions of the anticipated heavy $\sim Fe'$ component. This interpretation of the CDMSII/Ge events is a natural one given that a) mirror dark matter predicts an event rate whic…
In an extended effective operator framework of isospin violating interactions with light mediators, we investigate the compatibility of the candidate signal of the CDMS-II-Si with the latest constraints from DarkSide-50 and XENON-1T, etc. We show that the constraints from DarkSide-50 which utilizes Argon as the target is complementary to that from XENON-1T which utilizes Xenon. Combining the results of the two experiments, we find that for isospin violating interaction with light mediator there is no parameter space which can be compatible with the positive signals from CDMS-II-Si. As a concre…
Signals broadly compatible with light (7-10 GeV) dark matter have been reported in three direct detection experiments: CoGeNT, DAMA/LIBRA, and CDMS-II silicon. These possible signals have been interpreted in the context of spin-independent interactions between the target nuclei and dark matter, although there is tension with null results, particularly from xenon-based experiments. In this paper, we demonstrate that the CoGeNT and CDMS-II silicon results are also compatible assuming a spin-dependent neutron interaction, though this is in tension with xenon-based experiments and PICASSO. The ten…
We study dark matter that inelastically scatters and de-excites in direct detection experiments, as an interpretation of the CDMS-Si events in light of the recent LUX data. The constraints from LUX and XENON10 require the mass-splitting between the DM excited and de-excited states to be $|δ| \gtrsim 50$ keV. At the same time, the CDMS-Si data itself do not allow for a consistent DM interpretation for mass splittings larger than $|δ| \sim $200 keV. We find that a low threshold analysis will be needed to rule out this interpretation of the CDMS-Si events. In a simple model with a kinetically mix…
We present an updated halo-dependent and halo-independent analysis of viable light WIMP dark matter candidates which could account for the excess observed in CDMS-II-Si. We include recent constraints from LUX, PandaX-II, and PICO-60, as well as projected sensitivities for XENON1T, SuperCDMS SNOLAB, LZ, DARWIN, DarkSide-20k, and PICO-250, on candidates with spin-independent isospin conserving and isospin-violating interactions, and either elastic or exothermic scattering. We show that there exist dark matter candidates which can explain the CDMS-II-Si data and remain very marginally consistent …
The CDMS Collaboration has presented its results for the final exposure of the CDMS II experiment and reports that two candidate events for dark matter would survive after application of the various discrimination and subtraction procedures inherent in their analysis. We show that a population of relic neutralinos, which was already proved to fit the DAMA/LIBRA data on the annual modulation effect, could naturally explain the two candidate CDMS II events, if these are actually due to a dark matter signal.
Recently, the DAMA/LIBRA experiment has convincingly confirmed the DAMA/NaI annual modulation signal, experimentally demonstrating the existence of non-baryonic dark matter in the halo of our galaxy. Meanwhile, in another part of town, other experiments such as CDMS and XENON10 have not detected any evidence for dark matter. One promising dark matter candidate which can reconcile the positive DAMA annual modulation signal with the null results from the other experiments, is mirror dark matter. We re-analyse the mirror matter interpretation of the DAMA annual modulation signal utilizing a) the …
We perform a global fit to data from Dark Matter (DM) direct detection experiments, including the recent CDMS-II results. We discuss possible interpretations of the DAMA annual modulation signal in terms of spin-independent and spin-dependent DM-nucleus interactions, both for elastic and inelastic scattering. We find that in the spin-dependent inelastic scattering off protons a good fit to all data is obtained. We present a simple toy model realizing such a scenario. In all the remaining cases the DAMA allowed regions are disfavored by other experiments or suffer from severe fine tuning of DM …
We complete an investigation of the observable signatures of No-Scale flipped SU(5) x U(1)_X grand unified theory with TeV-scale vector-like particles (No-Scale F-SU(5)) at the LHC and dark matter direct detection experiments. We feature a dark matter candidate which is over 99% bino due to a comparatively large Higgs bilinear mass mu term around the electroweak scale, and hence automatically satisfy the present constraints from the XENON100 and CDMS/EDELWEISS experiments. We do however expect that the continued XENON100 run and extension to 1-ton may begin to probe our model. Similarly, our m…
Savage et al. have recently put forward the claim that results from the XENON10 experiment are incompatible with the totality of both DAMA/LIBRA and CoGeNT experimental regions. In this brief note the source of this erroneous conclusion is identified in a misinterpretation of the XENON10 efficiency in the detection of S1 light from low-energy nuclear recoils.
We consider models of xenophobic dark matter, in which isospin-violating dark matter-nucleon interactions significantly degrade the response of xenon direct detection experiments. For models of near-maximal xenophobia, with neutron-to-proton coupling ratio $f_n / f_p \approx -0.64$, and dark matter mass near 8 GeV, the regions of interest for CoGeNT and CDMS-Si and the region of interest identified by Collar and Fields in CDMS-Ge data can be brought into agreement. This model may be tested in future direct, indirect, and collider searches. Interestingly, because the natural isotope abundance o…
In the scenario of isospin-violating dark matter (IVDM), the dark matter (DM) spin-independent couplings to protons and to neutrons are allowed to be different, which has been considered to relax the tensions between the results of DAMA, CoGeNT and XENON experiments. We explore the allowed values of DM-nucleon couplings favored and excluded by the current experiments under the assumption of IVDM. We find that the recently updated XENON100 result excludes the main part of the overlapping signal region between DAMA and CoGeNT. The mass of the IVDM is restricted to a narrow range near 7.5-8 GeV. …
We present two examples of velocity distributions for light dark matter particles that reconcile the annual modulation signal observed by DAMA with all other negative results from dark matter searches. They are: (1) a conventional Maxwellian distribution for particle masses of 6 to 9 GeV; (2) a dark matter stream coming from the general direction of Galactic rotation (not the Sagittarius stream). Our idea is based on having a signal in Na, instead of I, in DAMA, and can be tested in the immediate future by CDMS-II (using Si) and CRESST-II (using O).
We consider the compatibility of DAMA/LIBRA, CoGeNT, XENON10 and XENON100 results for spin-independent (SI) dark matter Weakly Interacting Massive Particles (WIMPs), particularly at low masses (~ 10 GeV), assuming a standard dark matter halo. The XENON bounds depend on the scintillation efficiency factor Leff for which there is considerable uncertainty. Thus we consider various extrapolations for Leff at low energy. With the Leff measurements we consider, XENON100 results are found to be insensitive to the low energy extrapolation. We find the strongest bounds are from XENON10, rather than XEN…
The CoGeNT and DAMA/LIBRA experiments have found evidence for the spin-independent scattering from nuclei of a light dark matter (DM) particle, 7-12 GeV, which is not excluded by the XENON DM experiments. We show that this putative DM signal can be explained by a complex scalar singlet extension of the standard model (CSM), with a thermal cosmological DM density, and a Higgs sector that is consistent with LEP constraints. We make predictions for the masses, production, and decays of the two Higgs mass eigenstates and describe how the Higgs and DM particles can be discovered at the LHC.
The CRESST-II collaboration have announced evidence for the direct detection of dark matter in 730 kg-days exposure of a CaWO$_4$ target. We examine these new results, along with DAMA and CoGeNT data, in the context of the mirror dark matter framework. We show that all three experiments can be simultaneously explained via kinetic mixing induced elastic scattering of a mirror metal component off target nuclei. This metal component can be as heavy as Fe$'$ if the galactic rotational velocity is relatively low: $v_{rot} \stackrel{<}{\sim} 220$ km/s. This explanation is consistent with the constra…
We present two examples of velocity distributions for light dark matter particles that reconcile the annual modulation signal observed by DAMA with all other negative results from dark matter searches. They are: (1) a conventional Maxwellian distribution for particle masses around 5 to 9 GeV; (2) a dark matter stream coming from the general direction of Galactic rotation (not the Sagittarius stream). Our idea is based on attributing the DAMA signal to scattering off Na, instead of I, and can be tested in the immediate future by detectors using light nuclei, such as CDMS-II (using Si) and CRESS…
Dark matter candidates with electromagnetic dipole moments can arise as dark baryons in gauge-mediated or technicolor models. These dark matter candidates interact with nuclei in direct detection experiments mainly through magnetic and/or electric dipole moments. The scattering cross sections depend on the nuclear magnetic moments and nuclear charge and have an infrared enhancement compared with typical WIMP constant contact interactions, leading to distinctive nuclear recoil energy spectra. These characteristics result in an enhanced signal for the DAMA experiment compared with the CDMS or XE…
We extend the Standard Model by adding two gauge-singlet $\mathbb{Z}_{2}$% -symmetric scalar fields that interact with visible matter only through the Higgs particle. One is a stable dark matter WIMP, and the other one undergoes a spontaneous breaking of the symmetry that opens new channels for the dark matter annihilation, hence lowering the mass of the WIMP. We study the effects of the observed dark matter relic abundance on the annihilation cross section and find that in most regions of the parameters space, light dark matter is viable. We also compare the elastic scattering cross-section o…
Dark matter (DM) direct detections are investigated for models with the following properties: isospin-violating couplings, exothermic scatterings, and/or a light mediator, with the aim to reduce the tension between the CDMS-Si positive signals and other negative searches. In particular, we focus on the non-standard effective operators which could lead to the spin-independent DM-nucleus scatterings with non-trivial dependences on the transfer momentum or DM velocity. As a result, such effective operator choices have the very mild effects on the final fittings. Furthermore, by including the late…
For many years annually modulating $\sim$ keV scintillations have been observed in the DAMA/NaI and DAMA/Libra experiments. A dark matter - electron scattering interpretation is now favoured given the stringent constraints on nuclear recoil rates obtained by LUX, SuperCDMS and other experiments. Very recently, the XENON100 experiment has observed a modest annual modulation in their electron recoil events (2.8 $σ$ C.L.) with phase consistent with that of the DAMA experiments. However, they also found a stringent upper limit on the unmodulated rate, which suggests that any dark matter - electron…
We discuss the neutrino constraints from solar and terrestrial dark matter (DM) annihilations in the inelastic dark matter (iDM) scenario after the recent CDMS II results. To reconcile the DAMA/LIBRA data with constraints from all other direct experiments, the iDM needs to be light ($m_χ< 100$ GeV) and have a large DM-nucleon cross section ($σ_n \sim$ 10$^{-4}$ pb in the spin-independent (SI) scattering and $σ_n \sim$ 10 pb in the spin-dependent (SD) scattering). The dominant contribution to the iDM capture in the Sun is from scattering off Fe/Al in the SI/SD case. Current bounds from Super-Ka…
Assuming the lightest neutralino solely composes the cosmic dark matter, we examine the constraints of the CDMS-II and XENON100 dark matter direct searches on the parameter space of the MSSM Higgs sector. We find that the current CDMS-II/XENON100 limits can exclude some of the parameter space which survive the constraints from the dark matter relic density and various collider experiments. We also find that in the currently allowed parameter space, the charged Higgs boson is hardly accessible at the LHC for an integrated luminosity of 30 fb^{-1}, while the neutral non-SM Higgs bosons (H,A) may…
The CDMS II experiment has observed three events which may have arisen from weakly interacting massive particle (WIMP) dark matter (DM) with mass of order 9 GeV colliding with nuclei. Although the implied WIMP parameter region seems to be excluded by limits from the XENON experiments, it is interesting that most of this tension can go away if the WIMP-nucleon interaction violates isospin. This motivates us to explore some of the implications for models in which a real gauge-singlet scalar particle, the darkon, serves as the WIMP, taking into account the recent discovery of a Higgs boson at the…
In light of recent positive results from the DAMA experiment, as well as new null results from CDMS Soudan, Edelweiss, ZEPLIN-I and CRESST, we reexamine the framework of inelastic dark matter with a standard halo. In this framework, which was originally introduced to reconcile tensions between CDMS and DAMA, dark matter particles can scatter off of nuclei only by making a transition to a nearly degenerate state that is roughly $100 \kev$ heavier. We find that recent data significantly constrains the parameter space of the framework, but that there are still regions consistent with all experime…
We study a simple model that can give rise to isospin-violating interactions of Dirac fermion asymmetric dark matter to protons and neutrons through the interference of a scalar and U(1)$'$ gauge boson contribution. The model can yield a large suppression of the elastic scattering cross section off Xenon relative to Silicon thus reconciling CDMS-Si and LUX results while being compatible with LHC findings on the 126 GeV Higgs, electroweak precision tests and flavour constraints.
The effect of the chosen analysis energy window on the results of a dark matter experiment is exemplified by the curious intersection of the exclusion plots of the XENON10 and the CDMS experiments. After proving that the narrow energy window XENON10 chose to analyze is indeed the cause of such intersection, a method to determine the high-energy extreme of the recoil energy window an experiment should use is obtained.
Scattering of light dark matter (LDM) particles with atomic electrons is studied in the context of effective field theory. Contact and long-range interactions between dark matter and an electron are both considered. A state-of-the-art many-body method is used to evaluate the spin-independent atomic ionization cross sections of LDM-electron scattering, with an estimated error about 20%. New upper limits are derived on parameter space spanned by LDM mass and effective coupling strengths using data from the CDMSlite, XENON10, XENON100, and XENON1T experiments. Comparison with existing calculation…
We extend the halo-independent method of Fox, Liu, and Weiner to include energy resolution and efficiency with arbitrary energy dependence, making it more suitable for experiments to use in presenting their results. Then we compare measurements and upper limits on the direct detection of low mass ($\sim10$ GeV) weakly interacting massive particles with spin-independent interactions, including the upper limit on the annual modulation amplitude from the CDMS collaboration. We find that isospin-symmetric couplings are severely constrained both by XENON100 and CDMS bounds, and that isospin-violati…
We investigate the possibility for the direct detection of low mass (GeV scale) WIMP dark matter in scintillation experiments. Such WIMPs are typically too light to leave appreciable nuclear recoils, but may be detected via their scattering off atomic electrons. In particular, the DAMA Collaboration [R. Bernabei et al., Nucl. Phys. At. Energy 19, 307 (2018)] has recently presented strong evidence of an annual modulation in the scintillation rate observed at energies as low as 1 keV. Despite a strong enhancement in the calculated event rate at low energies, we find that an interpretation in ter…
Recently, the CDMS/Si experiment has observed a low energy excess of events in their dark matter search. In light of this new result we update the mirror dark matter explanation of the direction detection experiments. We find that the DAMA, CoGeNT, CRESST-II and CDMS/Si data can be simultaneously explained by halo $\sim Fe'$ interactions provided that $v_{rot} \approx 200$ km/s. Other parameter space is also possible. Forthcoming experiments, including CDMSlite, CDEX, COUPP, LUX, C-4,... should be able to further scrutinize mirror dark matter and closely related hidden sector models in the nea…
Three dark matter direct detection experiments, DAMA, COGENT and CRESST, have reported a possible signal of WIMP interaction corresponding to very light particles, close to the edge of the XENON 100 and CDMS sensitivity. Imposing the latest constraints from colliders, flavour physics, electroweak precision tests and direct and indirect dark matter searches, we show that viable MSSM scenarios with a light neutralino, in agreement with all the present data, are feasible. An analysis of the characteristics of the resulting scenarios will be presented.
DAMA annual modulation data and, CoGeNT, CDMS-II, EDELWEISS-II, CRESST excesses of events over the expected background are reanalyzed in terms of a dark matter particle signal considering the case of a rotating halo. It is found that DAMA data favor the configurations of very high mass dark matter particles in a corotating cold flux. A similar high-mass/low-velocity solution would be compatible with the observed events in CoGeNT, CDMS-II, EDELWEISS-II and CRESST experiments and could be of interest in the light of the positron/electron excess measured by Pamela and Fermi in cosmic rays.
We consider the hypothesis that Dark Matter (DM) has tree-level interactions only with leptons. Such a framework, where DM recoils against electrons bound in atoms, has been proposed as an explanation for the annually modulated scintillation signal in DAMA/LIBRA versus the absence of a signal for nuclear recoils in experiments like CDMS or XENON10. However, even in such a leptophilic DM scenario there are loop induced DM-hadron interactions, where the photons emitted from virtual leptons couple to the charge of a nucleus. Using a general effective field theory approach we show that, if such an…
We study the effect of a long-range DM-nuclei interaction occurring via the exchange of a light mediator. We consider the main direct detection experiments: DAMA, CoGeNT, CRESST, CDMS and XENON100. We find that a long-range force is a viable mechanism, which can provide full agreement between the various experiments, especially for masses of the mediator in the 10-30 MeV range and a light DM with a mass around 10 GeV. The relevant bounds on the light mediator mass and scattering cross section are then derived.
We study whether spin-independent scattering of weakly-interacting massive particles (WIMPs) with nuclei can account for the annual modulation signal reported by DAMA. We consider both elastic and inelastic scattering processes. We find that there is a region of WIMP parameter space which can simultaneously accommodate DAMA and the null results of CDMS, CRESST, and XENON. This region corresponds to an ordinary, elastically-scattering WIMP with a standard Maxwell-Boltzmann distribution, a mass 3 GeV < m_{DM} <8 GeV, and a spin-independent cross section with nucleons 3 \times 10^{-41} cm^2 < σ_p…
In these proceedings, I report on the status of a simple singlet scalar dark matter model in the light of recent results from both direct detection experiments, in particular DAMA, CoGeNT, CDMS-II and Xenon10/100, and indirect searches, in particular Fermi-LAT. Specifically, I confront the light scalar WIMP candidates, M_DM ~ few GeV, that are consistent with CoGeNT and/or DAMA, to constraints that may be set using the recent Fermi-LAT data on Milky Way dwarf spheroidal galaxies (dSphs) and the isotropic diffuse gamma-ray emission. I show that the latter observations set relevant exclusion lim…
In an extended effective operator framework, we investigate in detail the effects of light mediators on the event spectra of dark matter (DM)-nucleus scatterings. The presence of light mediators changes the interpretation of the current experimental data, especially the determination of DM particle mass. We show by analytic and numerical illustrations that for all the operators relevant to spin-independent scatterings, the DM particle mass allowed by the data increases significantly when the mediator particle becomes lighter. For the data of CDMS-II-Si, the allowed DM particle mass can reach $…
We present comparisons of direct detection data for "light WIMPs" with an anapole moment interaction (ADM) and a magnetic dipole moment interaction (MDM), both assuming the Standard Halo Model (SHM) for the dark halo of our galaxy and in a halo-independent manner. In the SHM analysis we find that a combination of the 90% CL LUX and CDMSlite limits or the new 90% CL SuperCDMS limit by itself exclude the parameter space regions allowed by DAMA, CoGeNT and CDMS-II-Si data for both ADM and MDM. In our halo-independent analysis the new LUX bound excludes the same potential signal regions as the pre…
Dark Matter candidates are natural in Technicolor theories. We introduce a general framework allowing to predict signals of Technicolor Dark Matter at colliders and set constraints from earth based experiments such as CDMS and XENON. We show that the associate production of the composite Higgs can lead to relevant signals at the Large Hadron Collider.
The CoGeNT collaboration has reported evidence of an annual modulation in its first fifteen months of data. Here we compare the amplitude and phase of this signal to the modulation observed by the DAMA collaboration, assuming that both arise due to elastically scattering dark matter (DM). We directly map the CoGeNT signal to the DAMA detector without specifying any astrophysical parameters and compare this with the signal measured by DAMA. We also compare with constraints from CDMS II and XENON10. We find that DM of mass 5-14 GeV that couples equally to protons and neutrons is strongly disfavo…
The determination of dark matter constraints from liquid xenon direct detection experiments depends upon the amount of scintillation light produced by nuclear recoils in the detector, a quantity that is characterized by the scintillation efficiency factor Leff. We examine how uncertainties in the measurements of Leff and the extrapolated behavior of Leff at low recoil energies (where measurements do not exist) affect the constraints from experiments such as XENON10 and XENON100, particularly in the light WIMP regions of interest for the DAMA and CoGeNT experimental results.
In this paper, we study the recent excess of low energy events observed by the CoGeNT collaboration, and discuss the possibility that these events originate from the elastic scattering of a light (m_DM ~ 5-10 GeV) dark matter particle. We find that such a dark matter candidate may also be capable of generating the annual modulation reported by DAMA, as well as the small excess recently reported by CDMS, without conflicting with the null results from other experiments, such as XENON10. A dark matter interpretation of the CoGeNT and DAMA observations favors a region of parameter space that is es…
