We discuss the most sensitive constraints on Light Dark Matter (LDM) from accelerator experiments NA64 and BaBar and compare it with recent results from direct searches at XENON1T, DAMIC-M, SuperCDMS, and DarkSide-50. We show that for the dark photon ($A'$) model with scalar LDM, NA64 gives more stringent bounds for $A'$ masses $m_{A'} \leq 0.15~GeV$ than direct searches. Moreover, for the case of Majorana LDM the damping DM velocity $v$ factor, $v^2 \sim O(10^{-6})$, for the elastic LDM electron(nucleon) cross section makes direct observation of Majorana LDM extremely challenging, while the absence of this suppression in the NA64 case gives an advantage to the experiment. The similar situation takes place for pseudo-Dirac LDM. The BaBar provides the most stringent bounds for $A'$ masses $m_{A'} \geq 0.35~GeV$. For scalar LDM the direct detection experiments give more stringent bounds at $m_{A'} \geq 0.35~GeV$ while for Majorana and pseudo-Dirac LDM case, the BaBar bounds are more stringent. The complementarity of the two approaches in searching for LDM is underlined.
We study the complementarity between accelerator and reactor coherent elastic neutrino-nucleus elastic scattering (CE$ν$NS) experiments for constraining new physics in the form of non-standard neutrino interactions (NSI). Firstly, considering just data from the recent observation by the COHERENT experiment, we explore interpretive degeneracies that emerge when activating either two or four unknown NSI parameters. Next, we demonstrate that simultaneous treatment of reactor and accelerator experiments, each employing at least two distinct target materials, can break a degeneracy between up and d…
We describe current and future hadron collider limits on new vector-like leptons with exotic decays. We consider the possibility that, besides standard decays, the new leptons can also decay into a Standard Model charged lepton and a stable particle like a dark photon. To increase their applicability, our results are given in terms of arbitrary branching ratios in the different decay channels. In the case that the dark photon is stable at cosmological scales we discuss the interplay between the dark photon and the vector-like lepton in generating the observed dark matter relic abundance and th…
We consider models of dark matter where the couplings between the standard model and the dark sector fall at resonance due to kinematics and direct detection experiments become insensitive. To be specific, we consider a simple model of 100 GeV - TeV scale dark matter coupled to the standard model via a vector boson. We explore whether it will be possible to exclude such regions of the parameter space using future observations of dijet rates at the LHC and CTA and AMS observations of the Galactic Centre.
Z' gauge bosons arise in many particle physics models as mediators between the dark and visible sectors. We exploit dark matter complementarity and derive stringent and robust collider, direct and indirect constraints, as well as limits from the muon magnetic moment. We rule out almost the entire region of the parameter space that yields the right dark matter thermal relic abundance, using a generic parametrization of the Z'-fermion couplings normalized to the Standard Model Z-fermion couplings for dark matter masses in the 8 GeV-5 TeV range. We conclude that mediators lighter than 2.1 TeV are…
We perform a combined fit to global neutrino oscillation data available as of fall 2016 in the scenario of three-neutrino oscillations and present updated allowed ranges of the six oscillation parameters. We discuss the differences arising between the consistent combination of the data samples from accelerator and reactor experiments compared to partial combinations. We quantify the confidence in the determination of the less precisely known parameters $θ_{23}$, $δ_\text{CP}$, and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We…
We discuss the phenomenology of an MeV-scale Dirac fermion coupled to the Standard Model through a dark photon with kinetic mixing with the electromagnetic field. We compute the dark matter relic density and explore the interplay of direct detection and accelerator searches for dark photons. We show that precise measurements of the temperature and polarization power spectra of the Cosmic Microwave Background Radiation lead to stringent constraints, leaving a small window for the thermal production of this MeV dark matter candidate. The forthcoming MeV gamma-ray telescope e-ASTROGAM will offer …
Nowadays there is an active discussion about the definition of Simplified Models of Dark Matter (SMDM) as a tool for interpreting LHC searches. Here we point out an additional simplified set-up which captures a very well motivated mechanism beyond the Standard Model: the kinetic-mixing of an extra U'(1) gauge symmetry. In addition to that, even if most of the attention has being paid on LHC "mono-signals", here we highlight an unavoidable signature appearing in SMDM with s-channel mediators: dijets or dileptons with no missing energy. We translate these searches into lower bounds on the DM cou…
In single-component theories of dark matter, the $2\to 2$ amplitudes for dark-matter production, annihilation, and scattering can be related to each other through various crossing symmetries. These crossing relations lie at the heart of the celebrated complementarity which underpins different existing dark-matter search techniques and strategies. In multi-component theories of dark matter, by contrast, there can be many different dark-matter components with differing masses. This then opens up a new, "diagonal" direction for dark-matter complementarity: the possibility of dark-matter decay fro…
We study the direct-detection rate for axial-vectorial dark matter scattering off nuclei in an $\mathrm{SU}(2)\times \mathrm{U}(1)$ invariant effective theory and compare it against the LHC reach. Current constraints from direct detection experiments are already bounding the mediator mass to be well into the TeV range for WIMP-like scenarios. This motivates a consistent and systematic exploration of the parameter space to map out possible regions where the rates could be suppressed. We do indeed find such regions and proceed to construct consistent UV models that generate the relevant effectiv…
In most multi-component dark-matter scenarios, two classes of processes generically contribute to event rates at experiments capable of probing the nature of the dark sector. The first class consists of "diagonal" processes involving only a single species of dark-matter particle -- processes analogous to those which arise in single-component dark-matter scenarios. By contrast, the second class consists of "off-diagonal" processes involving dark-matter particles of different species. Such processes include inelastic scattering at direct-detection experiments, asymmetric production at colliders,…
We consider models with the $U(1)_X$ gauge symmetry, which is spontaneously broken by dark Higgs mechanism. We discuss patterns of the electroweak phase transition and detectability of gravitational waves (GWs) when strongly first order phase transition (1stOPT) occurs. It is pointed out that the collider bounds on the properties of the discovered Higgs boson exclude a part of parameter space that could otherwise generate detectable GWs. We find that GWs produced from multi-step PT can be detected at future observations such as LISA and DECIGO if the dark photon mass is $m_X^{} \gtrsim 25$ GeV…
We analyze the potential of accelerator-based neutrino experiments, such as the Deep Underground Neutrino Experiment, to constrain a five dimensional operator mediating a beyond standard model interaction between mass dimension one fermion fields, labeled elko, and neutrino. We identify the parameter space where elko is a viable dark matter candidate.
Dark matter particles may interact with other dark matter particles via a new force mediated by a dark photon, $A^{\prime}$, which would be the dark-sector analog to the ordinary photon of electromagnetism. The dark photon can obtain a highly suppressed mixing-induced coupling to the electromagnetic current, providing a portal through which dark photons can interact with ordinary matter. This review focuses on $A^{\prime}$ scenarios that are potentially accessible to accelerator-based experiments. We summarize the existing constraints placed by such experiments on dark photons, highlight what …
Dark Matter experiments searching for Weakly interacting massive particles (WIMPs) primarily use nuclear recoils (NRs) in their attempt to detect WIMPs. Migdal-induced electronic recoils (ERs) provide additional sensitivity to light Dark Matter with $\mathcal{O}(\text{GeV}/c^2)$ masses. In this work, we use Bayesian inference to find the parameter space where future detectors like XENONnT and SuperCDMS SNOLAB will be able to detect WIMP Dark Matter through NRs, Migdal-induced ERs or a combination thereof. We identify regions where each detector is best at constraining the Dark Matter mass and …
We explore the possibility of having a fermionic dark matter candidate within $U(1)'$ models for CE$ν$NS experiments in light of the latest COHERENT data and the current and future dark matter direct detection experiments. A vector-like fermionic dark matter has been introduced which is charged under $U(1)'$ symmetry, naturally stable after spontaneous symmetry breaking. We perform a complementary investigation using CE$ν$NS experiments and dark matter direct detection searches to explore dark matter as well as $Z^{\prime}$ boson parameter space. Depending on numerous other constraints arising…
Direct detection dark matter experiments looking for WIMP-nucleus elastic scattering will soon be sensitive to an irreducible background from neutrinos which will drastically affect their discovery potential. Here we explore how the neutrino background will affect future ton-scale experiments considering both spin-dependent and spin-independent interactions. We show that combining data from experiments using different targets can improve the dark matter discovery potential due to target complementarity. We find that in the context of spin-dependent interactions, combining results from several …
Dark Matter Complementarity in the pMSSM and the ILC
寻找和潜在的暗物质（DM）的识别将需要一个同时的，多管齐下的方法，由大型强子对撞机，直接和间接DM检测实验，并最终，ILC发挥重要作用。19参数p（现象学）MSSM可以为中性伴子DM的互补性研究提供一个广泛的框架。在这次演讲中，我总结了这些搜索在7，8和14 TeV LHC的灵敏度，结合了\Fermi，CTA，IceCube/DeepCore，COUPP，LZ和XENON的搜索。这些搜索的优点和缺点进行了简要的讨论，因为它们是相互依存的作用，在探测pMSSM模型参数空间。我也评论未来的作用，国际法委员会在探索的详细性质的中性伴子DM。
The non-relativistic effective theory of dark matter-nucleon interactions depends on 28 coupling strengths for dark matter spin up to 1/2. Due to the vast parameter space of the effective theory, most experiments searching for dark matter interpret the results assuming that only one of the coupling strengths is non-zero. On the other hand, dark matter models generically lead in the non-relativistic limit to several interactions which interfere with one another, therefore the published limits cannot be straightforwardly applied to model predictions. We present a method to determine a rigorous u…
We explore the pMSSM parameter space in view of the constraints from SUSY and monojet searches at the LHC, from Higgs data and flavour physics observables, as well as from dark matter searches. We show that whilst the simplest SUSY scenarios are already ruled out, there are still many possibilities left over in the pMSSM. We discuss the complementarity between different searches and consistency checks which are essential in probing the pMSSM and will be even more important in the near future with the next round of data becoming available.
We explore the possibility that bound states involving dark matter particles could be detected by resonance searches at the LHC, and the generic implications of such scenarios for indirect and direct detection. We demonstrate that resonance searches are complementary to mono-jet searches and can probe dark matter masses above 1 TeV with current LHC data. We argue that this parameter regime, where the bound-state resonance channel is the most sensitive probe of the dark sector, arises most naturally in the context of non-trivial dark sectors with large couplings, nearly-degenerate dark-matter-l…
Some doubts have been expressed about low energy supersymmetry (SUSY) following the first run of the LHC. In this talk I will try to present a more upbeat view based on data, rather than theoretical expectations. In particular, I will make the following points: (a) in my opinion the most attractive candidate for dark matter (DM) is now the lightest neutralino with mass around 1 TeV and with well defined properties (a nearly pure higgsino). This follows primarily from a combination of the properties of the discovered Higgs boson, in particular its mass close to 125 Gev, and the relic density of…
The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for variety of experimental data. The EW particles with masses of a few hundred GeV evade the LHC searches owing to their small production cross sections. Such a light EW sector can in particular explain the reinforced $4.2\,σ$ discrepancy between the experimental result for the anomalous magnetic moment of the muon, \gmin2, and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), assumed to be the lightest neutralino, $\tildeχ_1^0$, as a Dark Matter (DM) candidate is furtherm…
The fundamental nature of Dark Matter is a central theme of the Snowmass 2021 process, extending across all Frontiers. In the last decade, advances in detector technology, analysis techniques and theoretical modeling have enabled a new generation of experiments and searches while broadening the types of candidates we can pursue. Over the next decade, there is great potential for discoveries that would transform our understanding of dark matter. In the following, we outline a road map for discovery developed in collaboration among the Frontiers. A strong portfolio of experiments that delves dee…
We present an extensive analysis of a model in which the (Majorana) Dark Matter candidate is a mixture between a SU(2) singlet and two SU(2) doublets. This kind of setup takes the name of singlet-doublet model. We will investigate in detail an extension of this model in which the Dark Matter sector interactions with a 2-doublet Higgs sector enforcing the complementarity between Dark Matter phenomenology and searches of extra Higgs bosons.
The problems of simple elementary weakly interacting massive particles (WIMPs) appeal to extend the physical basis for nonbaryonic dark matter. Such extension involves more sophisticated dark matter candidates from physics beyond the Standard Model (BSM) of elementary particles. We discuss several models of dark matter, predicting new colored, hyper-colored or techni-colored particles and their accelerator and non-accelerator probes. The nontrivial properties of the proposed dark matter candidates can shed new light on the dark matter physics. They provide interesting solutions for the puzzles…
Constraining dark matter models necessitates accurate predictions for large set of observables originating from collider physics, cosmology and astrophysics. We consider two classes of top-philic dark matter models where the dark sector is coupled to the Standard Model via the top quark and study the complementarity of dark matter relic density, direct and indirect detection and collider searches in exploring the model parameter space. We moreover investigate how higher-order corrections affect the results.
We examine the capabilities of planned direct detection, indirect detection, and collider experiments in exploring the 19-parameter p(henomenological)MSSM, focusing on the complementarity between the different search techniques. In particular, we consider dark matter searches at the 7, 8 (and eventually 14) TeV LHC, \Fermi, CTA, IceCube/DeepCore, and LZ. We see that the search sensitivities depend strongly on the WIMP mass and annihilation mechanism, with the result that different search techniques explore orthogonal territory. We also show that advances in each technique are necessary to full…
Displaced vertices are relatively unusual signatures for dark matter searches at the LHC. We revisit the model of pseudo-Dirac dark matter (pDDM), which can accommodate the correct relic density, evade direct detection constraints, and generically provide observable collider signatures in the form of displaced vertices. We use this model as a benchmark to illustrate the general techniques involved in the analysis, the complementarity between monojet and displaced vertex searches, and provide a comprehensive study of the current bounds and prospective reach.
A natural possibility for dark matter is that it is composed of the stable pions of a QCD-like hidden sector. Existing literature largely assumes that pion self-interactions alone control the early universe cosmology. We point out that processes involving vector mesons typically dominate the physics of dark matter freeze-out and significantly widen the viable mass range for these models. The vector mesons also give rise to striking signals at accelerators. For example, in most of the cosmologically favored parameter space, the vector mesons are naturally long-lived and produce Standard Model p…
We investigate the phenomenology of a scalar top-philic dark matter candidate when adding a dimension-five contact interaction term, as motivated by possible underlying extensions of the Standard Model such as composite Higgs models. We show that the presence of contact interactions can have a major impact on the dark matter relic density as well as on its direct and indirect detection prospects, while the collider phenomenology of the model is unaffected. This underlines the complementarity of collider and cosmological constraints on dark matter models.
We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: the DM and mediator masses, and the mediator couplings to DM and quarks. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework can be used to establish an equal-…
Sub-GeV halo dark matter that enters the Sun can potentially scatter off hot solar nuclei and be ejected much faster than its incoming velocity. We derive an expression for the rate and velocity distribution of these reflected particles taking into account the Sun's temperature and opacity. We further demonstrate that future direct detection experiments could use these energetic reflected particles to probe light dark matter in parameter space that cannot be accessed via ordinary halo dark matter.
An Effective Field Theory for dark matter at a TeV-scale hadron collider should include contact interactions of dark matter with the partons, the Higgs and the Z. This note estimates the impact of including dark matter-Z interactions on the complementarity of spin dependent direct detection and LHC monojet searches for dark matter. Their effect is small, because they are suppressed by electroweak couplings and the contact interaction self-consistency condition $C/Λ^2 < 4π/\hat{s}$. In this note, the contact interactions between the Z and dark matter are parametrised by derivative operators; th…
