Dark Matter Direct Detection Experiments Research Articles

The new (g−2)μ and right-handed sneutrino dark matter

In this paper we investigate the (g−2)μ discrepancy in the context of the R-parity conserving next-to-minimal supersymmetric Standard Model plus right-handed neutrinos superfields. The model has the ability to reproduce neutrino physics data and includes the interesting possibility to have the right-handed sneutrino as the lightest supersymmetric particle and a viable dark matter candidate. Since right-handed sneutrinos are singlets, no new contributions for δaμ with respect to the MSSM and NMSSM are present. However, the possibility to have the right-handed sneutrino as the lightest supersymmetric particle opens new ways to escape Large Hadron Collider and direct detection constraints. In particular, we find that dark matter masses within 10≲mν˜R≲600 GeV are fully compatible with current experimental constraints. Remarkably, not only spectra with light sleptons are needed, but we obtain solutions with mμ˜≳600 GeV in the entire dark matter mass range that could be probed by new (g−2)μ data in the near future. In addition, dark matter direct detection experiments will be able to explore a sizable portion of the allowed parameter space with mν˜R≲300 GeV, while indirect detection experiments will be able to probe a much smaller fraction within 200≲mν˜R≲350 GeV.

Underground detections of an extra gauge interacting sterile neutrino dark matter

We show that decay products from sterile neutrino dark matter in extra U(1) models are detectable in both direct dark matter detection experiments and neutrino telescope. The sterile neutrino dark matter interacts with a light gauge boson and decays into neutrinos. Those neutrinos could scatter off nuclei with a large enough recoil energy in direct dark matter detection experiments as WIMPs do.

New Results from a Three-Year Annual Modulation Search with COSINE-100

COSINE-100 is a direct detection dark matter experiment that is testing DAMA/LIBRA’s claim of dark matter discovery. Located in South Korea’s Yangyang underground laboratory, C0SINE-100 comprises 106 kg of sodium iodide detectors surrounded by a ∼2000 L liquid scintillator veto. In this talk, I will present new results from an annual modulation search using three years of data and the impact on DAMA/LIBRA’s discovery claim. I will also discuss improvements over our previous modulation analysis, including lowering the analysis threshold to 1 keV and the development of a more robust time-dependent background model. In addition, I will review ongoing R&D projects for, and the physics reach of future phases of the experiment.

Fermionic singlet dark matter in one-loop solutions to the R_K anomaly: a systematic study

We study the dark matter phenomenology of Standard Model extensions addressing the reported anomaly in the R_K observable at one-loop. The article covers the case of fermionic singlet DM coupling leptophilically, quarkphilically or amphiphilically to the SM. The setup utilizes a large coupling of the new particle content to the second lepton generation to explain the R_K anomaly, which in return tends to diminish the dark matter relic density. Further, dark matter direct detection experiments provide stringent bounds even in cases where the dark matter candidate only contributes a small fraction of the observed dark matter energy density. In fact, direct detection rules out all considered models as an explanation for the R_K anomaly in the case of Dirac dark matter. Conversely, for Majorana dark matter, the R_K anomaly can be addressed in agreement with direct detection in coannihilation scenarios. For leptophilic dark matter this region only exists for M_text {DM} lesssim 1000 , mathrm {GeV} and dark matter is underabundant. Quarkphilic and amphiphilic scenarios even provide narrow regions of parameter space where the observed relic density can be reproduced while offering an explanation to R_K in agreement with direct detection experiments.

The impact of operator interference and target complementarity in dark matter direct detection experiments

We present a method to determine the limits on the DM-nucleon interaction strengths for one experiment in the non-relativistic effective theory by taking the interference of operators into account. Further, we extend the method to combine several experiments. To apply the developed methods, we use data from the XENON1T and PICO6O collaborations. The relaxation caused by the interference among operators can be up to four orders of magnitude. The strengthening of the limits by combining the analysis of both experiments can be up to four orders of magnitude.

Annual modulation results from three-year exposure of ANAIS-112

ANAIS-112 is a dark matter direct detection experiment that operates 112 kg of NaI(Tl) scintillators at the Canfranc Underground Laboratory (LSC, Spain). Its main goal is to test in a model independent way one of the most puzzling results in the present particle physics scenario: the DAMA/LIBRA observation of an annual modulation in the detection rate compatible with that expected for dark matter. This signal is in strong tension with the negative results of other very sensitive experiments. However, until recently a direct comparison using the same target material (NaI(Tl)) was lacking. ANAIS-112 has been taking data since August 2017 in stable conditions with excellent performance. Results from the first three years are compatible with the absence of modulation and incompatible with the DAMA/LIBRA measured modulation at more than 2.5σ C.L. This result supports the projected goal of reaching a 3σ sensitivity to the DAMA/LIBRA result for the scheduled five-year operation.

Electroweak symmetry non-restoration from dark matter

Restoration of the electroweak symmetry at temperatures around the Higgs mass is linked to tight phenomenological constraints on many baryogenesis scenarios. A potential remedy can be found in mechanisms of electroweak symmetry non-restoration (SNR), in which symmetry breaking is extended to higher temperatures due to new states with couplings to the Standard Model. Here we show that, in the presence of a second Higgs doublet, SNR can be realized with only a handful of new fermions which can be identified as viable dark matter candidates consistent with all current observational constraints. The competing requirements on this class of models allow for SNR at temperatures up to ∼TeV, and imply the presence of sub-TeV new physics with sizable interactions with the Standard Model. As a result this scenario is highly testable with signals in reach of next-generation collider and dark matter direct detection experiments.

Dark Matter Physics in Neutrino Telescopes and Neutrino Physics in Dark Matter Detectors

It is often the case that experiments built with a focus on a specific fundamental question are sensitive to a wider range of physical phenomena. In this proceedings I discuss two cases where new insights will come from experiments that have a different primary purpose. First, presents results from Ref. [1], which assesses what simple dark matter models will be uniquely probed by a upcoming Neutrino telescope inspired by KM3NeT. Given the existing constraints from γ-ray telescopes, measurements of the cosmic microwave background and direct dark matter detection, we focus on a secluded U(1)L μ − L γ model as particularly promising. Secondly, I present the results from Ref. [2], which describes how detecting solar neutrinos in direct dark matter detection experiments will be vital for confirming the possible U(1)L μ − L γ explanation of the anomalous magnetic moment of the muon.

Machine-learning techniques applied to three-year exposure of ANAIS–112

ANAIS is a direct dark matter detection experiment aiming at the confirmation or refutation of the DAMA/LIBRA positive annual modulation signal in the low energy detection rate, using the same target and technique. ANAIS–112, located at the Canfranc Underground Laboratory in Spain, is operating an array of 3×3 ultrapure NaI(Tl) crystals with a total mass of 112.5 kg since August 2017. The trigger rate in the region of interest (1-6 keV) is dominated by non-bulk scintillation events. In order to discriminate these noise events from bulk scintillation events, robust filtering protocols have been developed. Although this filtering procedure works very well above 2 keV, the measured rate from 1 to 2 keV is about 50% higher than expected according to our background model, and we cannot discard non-bulk scintillation events as responsible of that excess. In order to improve the rejection of noise events, a Boosted Decision Tree has been developed and applied. With this new PMT-related noise rejection algorithm, the ANAIS–112 background between 1 and 2 keV is reduced by almost 30%, leading to an increase in sensitivity to the annual modulation signal. The reanalysis of the three years of ANAIS–112 data with this technique is also presented.

The ASTAROTH Project: enhanced low-energy sensitivity to Dark Matter annual modulation

ASTAROTH is a novel R&D project which aims at improving the physics reach of future direct dark matter detection experiments based on NaI(Tl) scintillating crystals. There is a strong need to test the long standing DAMA positive observation of an annual modulation that could be due to Dark Matter (DM), with the same target material and in a model independent way. ASTAROTH aim is the enhancement of the sensitivity to the annual modulation signal, compared with present technology, by lowering the detection energy threshold in order to observe sub-keV recoils for the first time. This can be achieved by reading the scintillation light from the NaI(Tl) crystals with arrays of Silicon PhotoMultipliers (SiPM), and placing the detectors in a cryogenic environment. SiPMs feature lower dark noise than Photomultiplier Tubes (PMTs) at T < 150 K and allow for higher light collection. The cooling medium is liquid Argon, as it is an excellent scintillator that can be instrumented to act as a veto against several backgrounds.Here we present the status of the ASTAROTH project, introducing the innovative design of the detector chamber that will be used for the demonstration of the technology. Then, we will show the preliminary results of our first ever measurements performed on a single NaI(Tl) crystal read out by one SiPM array in a cryogenic set-up cooled with liquid nitrogen.

Neutrino and Axion Astronomy with Dark Matter Experiments

Sensitive dark matter (DM) experiments can be well exploited beyond their designated targets, allowing to explore a breadth of physics topics. As we discuss, future large direct DM detection experiments constitute impressive telescopes, complementary to conventional neutrino detectors. This opens a new window into neutrino astronomy, including puzzles such as the origin of supermassive black holes and topics like supernova forecast. Furthermore, DM experiments can act as effective instruments for multimessenger astronomy. This is well illustrated by exploration of relativistic axions from transient astrophysical sources (e.g. axion star explosions), providing novel signatures as well as possible insights into the axion potential.

210Pb measurements at the André E. Lalonde AMS Laboratory: Potential for the radioassay of materials used in rare event search detectors

210Pb (T1/2=22.2 y) is an important source of background in rare event searches, such as neutrinoless double-β decay and dark matter direct detection experiments. In this paper, the capabilities of the A.E. Lalonde AMS Laboratory at the University of Ottawa for 210Pb measurements are discussed.For fluoride targets, the blank 210Pb/206Pb ratio was in the 10−14 to 10−13 range, but (PbF3)− current output was lower and less stable. For oxide targets, (PbO2)− current output showed better stability, despite a significant difference in current output for commercial PbO and processed samples, and background studies suggested a background not much higher than that of the fluoride targets. Both target materials showed, therefore, good performance for 210Pb Accelerator Mass Spectrometry assay.Measurements of Kapton ultra-thin films were performed. 90% C.L. upper limits for the 210Pb specific activity in the range of 0.74–2.8 Bq/kg were established for several Kapton HN films.

Electroweak phase transition in a complex singlet extension of the Standard Model with degenerate scalars

We study the feasibility of strong first-order electroweak phase transition (EWPT) in a degenerate-scalar scenario of a complex singlet extension of the Standard Model, in which a mass of an additional scalar is nearly degenerate with that of the Higgs boson, 125 GeV. This scenario is known to provide an exquisite solution for circumventing constraints from dark matter direct detection experiments due to cancellations between two scattering amplitudes mediated by two scalars. In the analysis of EWPT, we employ two gauge-invariant calculation schemes on the scalar potential and two familiar resummation methods in evaluating one-loop (gauge dependent) effective potential. We point out that one of the conditions for the strong first-order EWPT is incompatible with the known suppression mechanism of a dark matter cross-section scattering off the nucleons. Nevertheless, we find that strong first-order EWPT is still possible in the degenerate-scalar scenario by dodging dark matter constraints differently.

Wino-Higgsino dark matter in MSSM from the g − 2 anomaly

In this letter, we show that the wino-Higgsino dark matter (DM) is detectable in near future DM direct detection experiments for almost all consistent parameter space in the spontaneously broken supergravity (SUGRA) if the muon g−2 anomaly is explained by the wino-Higgsino loop diagrams. We also point out that the present and future LHC experiments can exclude or confirm this SUGRA explanation of the observed muon g−2 anomaly.

One-loop corrections to ALP couplings

The plethora of increasingly precise experiments which hunt for axion-like particles (ALPs), as well as their widely different energy reach, call for the theoretical understanding of ALP couplings at loop-level. We derive the one-loop contributions to ALP-SM effective couplings, including finite corrections. The complete leading-order — dimension five — effective linear Lagrangian is considered. The ALP is left off-shell, which is of particular impact on LHC and accelerator searches of ALP couplings to γγ, ZZ, Zγ, WW, gluons and fermions. All results are obtained in the covariant Rξ gauge. A few phenomenological consequences are also explored as illustration, with flavour diagonal channels in the case of fermions: in particular, we explore constraints on the coupling of the ALP to top quarks, that can be extracted from LHC data, from astrophysical sources and from Dark Matter direct detection experiments such as PandaX, LUX and XENON1T. Furthermore, we clarify the relation between alternative ALP bases, the role of gauge anomalous couplings and their interface with chirality-conserving and chirality-flip fermion interactions, and we briefly discuss renormalization group aspects.

Exploring the origin of supermassive black holes with coherent neutrino scattering

Collapsing supermassive stars (M ≳ 3 × 104 M ☉) at high redshifts can naturally provide seeds and explain the origin of the supermassive black holes observed in the centers of nearly all galaxies. During the collapse of supermassive stars, a burst of non-thermal neutrinos is generated with a luminosity that could greatly exceed that of a conventional core collapse supernova explosion. In this work, we investigate the extent to which the neutrinos produced in these explosions can be observed via coherent elastic neutrino-nucleus scattering (CEνNS). Large scale direct dark matter detection experiments provide particularly favorable targets. We find that upcoming \U0001d4aa(100) tonne-scale experiments will be sensitive to the collapse of individual supermassive stars at distances as large as \U0001d4aa(10) Mpc.

Muon g−2 and coannihilating dark matter in the minimal supersymmetric standard model

We demonstrate that the recent measurement of the anomalous magnetic moment of the muon and dark matter can be simultaneously explained within the Minimal Supersymmetric Standard Model. Dark matter is a mostly-bino state, with the relic abundance obtained via co-annihilations with either the sleptons or wino. The most interesting regions of parameter space will be tested by the next generation of dark matter direct detection experiments.

Confirming U(1)_{L_mu -L_{tau }} as a solution for (g-2)_mu with neutrinos

The recent measurement of the muon anomalous magnetic moment by the Fermilab E989 experiment, when combined with the previous result at BNL, has confirmed the tension with the SM prediction at 4.2,sigma CL, strengthening the motivation for new physics in the leptonic sector. Among the different particle physics models that could account for such an excess, a gauged U(1)_{L_mu -L_{tau }} stands out for its simplicity. In this article, we explore how the combination of data from different future probes can help identify the nature of the new physics behind the muon anomalous magnetic moment. In particular, we contrast U(1)_{L_mu -L_{tau }} with an effective U(1)_{L_mu }-type model. We first show that muon fixed target experiments (such as NA64mu ) will be able to measure the coupling of the hidden photon to the muon sector in the region compatible with (g-2)_mu , and will have some sensitivity to the hidden photon’s mass. We then study how experiments looking for coherent elastic neutrino-nucleus scattering (CEnu NS) at spallation sources will provide crucial additional information on the kinetic mixing of the hidden photon. When combined with NA64mu results, the exclusion limits (or reconstructed regions) of future CEnu NS detectors will also allow for a better measurement of the mediator mass. Finally, the observation of nuclear recoils from solar neutrinos in dark matter direct detection experiments will provide unique information about the coupling of the hidden photon to the tau sector. The signal expected for U(1)_{L_mu -L_{tau }} is larger than for U(1)_{L_mu } with the same kinetic mixing, and future multi-ton liquid xenon proposals (such as DARWIN) have the potential to confirm the former over the latter. We determine the necessary exposure and energy threshold for a potential 5,sigma discovery of a U(1)_{L_mu -L_{tau }} boson, and we conclude that the future DARWIN observatory will be able to carry out this measurement if the experimental threshold is lowered to 1,{mathrm {keV}}_{mathrm {nr}} .

Probing mild-tempered neutralino dark matter through top-squark production at the LHC

The lightest neutralino, assumed to be the lightest supersymmetric particle, is proposed to be a dark matter (DM) candidate for the mass $\mathcal{O}(100)\text{ }\text{ }\mathrm{GeV}$. Constraints from various direct dark matter detection experiments and Planck measurements exclude a substantial region of parameter space of minimal supersymmetric standard model. However, a ``mild-tempered'' neutralino with dominant bino composition and a little admixture of Higgsino is found to be a viable candidate for DM. Within the minimal supersymmetric standard model framework, we revisit the allowed region of parameter space that is consistent with all existing constraints. Regions of parameters that are not sensitive to direct detection experiments, known as ``blind spots,'' are also revisited. Complimentary to the direct detection of DM particles, a mild-tempered neutralino scenario is explored at the LHC with the center of mass energy $\sqrt{\mathrm{s}}=13\text{ }\text{ }\mathrm{TeV}$ through the top-squark pair production, and its subsequent decays with the standard-model-like Higgs boson in the final state. Our considered channel is found to be very sensitive also to the blind spot scenario. Detectable signal sensitivities are achieved using the cut-based method for the high luminosity options 300 and $3000\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, which are further improved by applying the multivariate analysis technique.

Future prospects for the minimal supersymmetric standard model

Experimental collaborations for the large hadron collider conducted various searches for supersymmetry. In the absence of signals, lower limits were put on sparticle masses but usually within frameworks with (over-)simplifications relative to the entire indications by supersymmetry models. For complementing current interpretations of experimental bounds, we introduce a 30-parameter version of the R-parity conserving Minimal Supersymmetric Standard Model (MSSM-30). Using a sample of the MSSM-30 which are in harmony with cold dark matter, flavor and precision electroweak constraints, we explicitly show the prospects for assessing neutralino candidate dark matter in contrast to future searches for supersymmetry. The MSSM-30-parameter regions that are beyond reach to dark matter direct detection experiments could be probed by future hadron–hadron colliders.