Assuming that dark matter is a weakly interacting massive particle (WIMP) species X produced in the early Universe as a cold thermal relic, we study the collider signal of pp or ppbar -> XXbar + jets and its distinguishability from standard-model background processes associated with jets and missing energy. We assume that the WIMP is the sole particle related to dark matter within reach of the LHC--a "maverick" particle--and that it couples to quarks through a higher dimensional contact interaction. We simulate the WIMP final-state signal XXbar + jet and dominant standard-model (SM) background processes and find that the dark-matter production process results in higher energies for the colored final state partons than do the standard-model background processes, resulting in more QCD radiation and a higher jet multiplicity. As a consequence, the detectable signature of maverick dark matter is an excess over standard-model expectations of events consisting of large missing transverse energy, together with large leading jet transverse momentum and scalar sum of the transverse momenta of the jets. Existing Tevatron data and forthcoming LHC data can constrain (or discover!) maverick dark matter.
A maverick top partner model, decaying to a dark photon was suggested. The dark photon decays to two overlapping electrons for dark photon masses of $\approx 100$ GeV, and results in a so-called lepton-jet. The event includes a top quark as well, which results in events with two boosted objects, one heavy and the other light. We propose a search strategy exploiting the unique signal topology. We show that for a set of kinematic selections, both in hadronic and leptonic decay channel of the SM top quark, almost all background can be eliminated, leaving enough signal events up to top partner mas…
We study how to unravel the dark matter blind spots by phase transition gravitational waves in synergy with collider signatures at electroweak one-loop level taking the inert doublet model as an example. We perform a detailed Monte Carlo study at the future lepton colliders in the favored parameter space, which is consistent with current dark matter experiments and collider constraints. Our studies demonstrate that the Circular Electron Positron Collider and other future lepton colliders have the potential to explore the dark matter blind spots.
The notion that dark matter and standard-model matter are connected through flavor implies a generic collider signature of the type 2 jets + $μ^\pm$ + $e^\mp$ + missing energy. We discuss the theoretical basis of this proposal and its verifiability at the Large Hadron Collider.
We explore the possibility that the dark matter relic density is not produced by thermal mechanism directly, but by the decay of other heavier dark sector particles which on the other hand can be produced by the thermal freeze-out mechanism. Using a concrete model with a light dark matter from dark sector decay, we study the collider signature of the dark sector particles in association with Higgs production processes. We find that the future lepton colliders can be a better place to probe the signature of this kind of light dark matter model than the hadron collider such as LHC. Meanwhile, it…
We investigate the need and prospects for measuring dark matter properties at particle collider experiments. We discuss the connections between the inferred properties of particle dark matter and the physics that is expected to be uncovered by the Large Hadron Collider (LHC) and the International Linear Collider (ILC) and motivate the necessity of measuring detailed dark matter properties at a collider. We then investigate a model-independent signature of dark matter at a collider and discuss its observability. We next examine the prospects for making precise measurements of dark matter proper…
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.
The phenomenology of dark sector is complicated if dark sector is charged under a confined hidden gauge group. In such kind of model, a dark parton produced at a high energy collider showers and hadronize to a cluster of dark mesons. Dark mesons then decay to visible particles and produce a jet-like signal, which is called "dark jet" in this work. Collider signal of dark jet depends on the property of dark mesons. For example, a finite lifetime of dark meson would provide displaced vertex or displaced track, thus one can use these displaced objects to tag dark jet. However if the lifetime of 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 study the signatures of the triplet-quadruplet dark matter model at the LHC and future colliders, including the 100 TeV Super Proton-Proton Collider and the 240 GeV Circular Electron Positron Collider. The dark sector in this model contains one fermionic electroweak triplet and two fermionic quadruplets, which have two kinds of Yukawa couplings to the Higgs doublet. Electroweak production signals of the dark sector fermions in the $\text{monojet}+/\!\!\!\!E_\mathrm{T}$, disappearing track, and $\text{multilepton}+/\!\!\!\!E_\mathrm{T}$ channels at the LHC and the Super Proton-Proton Collide…
The cosmological phase transition with Q-balls production mechanism can explain the baryogenesis and dark matter simultaneously, where constraints on dark matter masses and reverse dilution are significantly relaxed. We study how to probe this scenario by collider signals at QCD next-to-leading order and gravitational wave signals.
The search for a dark photon produced at $e^{+}e^{-}$ colliders which subsequently decays into inelastic dark matter particles, is discussed. The heavier dark matter decays into a pair of visible charged particles and a lighter dark matter particle after traveling some distance. The visible decay products can be recorded by a dark matter detector made of emulsions and gas detectors, placed near the main $e^{+}e^{-}$ detector. This setup can not only explore new parameter regions not reached before, but also re-open some regions thought to be excluded by previous experimental data. The physics …
In this paper we study the possible searches at colliders using Vector Boson Fusion topology in the context of Simplified Models signatures. We examine the possible physics reach of these searches with regard to monojet-type searches, and determine how these two signatures are complementary.
We investigate the collider signatures of the three benchmark points in the singlet fermionic dark matter model. The benchmark points, which were introduced previously to explain the Fermi gamma-ray excess by dark matter (DM) pair annihilation at the Galactic center, have definite predictions for future collider experiments such as the International Linear Collider and the High-Luminosity LHC. We consider four collider observables: (1) Higgs signal strength (essentially $hZZ$ coupling), (2) triple Higgs coupling, (3) exotic Higgs decay, and (4) direct production of a new scalar particle. The b…
The accuracy in the measurement of the masses of sleptons and heavy Higgs bosons in cMSSM scenarios, compatible with the WMAP result on cold dark matter, has been re-analysed in view of the requirements for predicting this density to a few percent level from SUSY measurements at the linear collider.
Dark matter which interacts through a magnetic or electric dipole moment is an interesting possibility which may help to resolve the discrepancy between the DAMA annual modulation signal and the null results of other searches. In this article we examine relic density and collider constraints on such dark matter, and find that for couplings needed to explain DAMA, the thermal relic density is generically in the right ballpark to account for cosmological measurements. Collider constraints are relevant for light WIMPs, but less constraining that direct searches for masses above about 10 GeV.
We investigate the sensitivity to the effective operators describing interactions between dark matter particles and photons at future high energy $e^+e^-$ colliders via the $γ+ \slashed{E}$ channel. Such operators could be useful to interpret the potential gamma-ray line signature observed by the Fermi-LAT. We find that these operators can be further tested at $e^+ e^-$ colliders by using either unpolarized or polarized beams. We also derive a general unitarity condition for $2 \to n$ processes and apply it to the dark matter production process $e^+e^-\toχχγ$.
Dark sectors with strong interactions have received considerable interest. Assuming the existence of a minimally coupled dark sector which runs to strong interactions in the infrared, we address the question whether the scaling behavior of this dark sector can be observed in missing energy signatures at present and future hadron colliders. We compare these findings to the concrete case of self-interacting dark matter and demonstrate that the energy dependence of high-momentum transfer final states can in principle be used to gain information about the UV structure of hidden sectors at future h…
Light Dark Matter, $<10$ GeV, with sizable direct detection rate is an interesting and less explored scenario. Collider searches can be very powerful, such as through the channel in which a pair of dark matter particle are produced in association with a jet. It is a generic possibility that the mediator of the interaction between DM and the nucleus will also be accessible at the Tevatron and the LHC. Therefore, collider search of the mediator can provide a more comprehensive probe of the dark matter and its interactions. In this article, to demonstrate the complementarity of these two approach…
Minimal scenarios with light (sub-GeV) thermal dark matter are usually accompanied by a correspondingly light "dark sector". Taking as an example a simple fermionic dark matter model, we will show that the presence of the dark sector plays a key role in constraining such scenarios at accelerators experiments. The effect of including a dark Higgs boson in the light spectrum is in particular investigated.
Associated production of a dark particle and a photon, represented as a mono-$γ$ event, is a promising channel to probe particle contents and dynamics in the dark sector. In this paper we study properties of the mono-$γ$ production of a vector dark matter at future $e^+e^-$ colliders. The photon-like and Pauli operators, as well as triple gauge bosons interactions involving the dark matter, are considered in the framework of Effective Field Theory. We show that, comparing to the Pauli operator, the triple gauge bosons couplings are much more interesting at high energy collider. Beam polarizati…
If the length scale of possible extra dimensions is large enough, the effective Planck scale is lowered such that microscopic black holes could be produced in collisions of high-energy particles at colliders. These black holes evaporate through Hawking radiation of a handful of energetic particles drawn from the set of all kinematically and thermally allowed degrees of freedom, including dark matter. Here, we perform the first numerical black hole spectroscopic study of the dark sector. We find that if the next generation of colliders can produce microscopic black holes, then missing momentum …
Dark matter models can give rise to specific signatures at particle physics experiments or in cosmology. The details of the cosmological history can also influence the new physics signals to be expected at e.g. collider experiments. In these proceedings, we briefly summarize the case of dark matter weakly to feebly coupled to Standard Model fermions through t-channel portal dividing the discussion into three main regimes. We also underline the interplay between cosmology and particle physics.
We study the potential of neutralino dark matter searches and SUSY particle production at colliders in the framework of the Minimal Supersymmetric Standard Model. We show the effects of a non universal gluino mass parameter. The future experiments will be a stringent probe of the low energy MSSM and neutralino dark matter scenario. The deeper informations on both supersymmetry and astrophysics hypothesis will be obtained by correlation of the different signals or absence of signal.
Dark Matter is a hypothetical particle proposed to explain the missing matter expected from the cosmological observation. The motivation of Dark Matter is overwhelming however as it is mainly deduced from its gravitational interaction, for it does little to pinpoint what Dark Matter really is. In WIMPs Miracle, weakly interactive massive particle being the Dark Matter candidate is correctly producing the current thermal relic density at weak scale, implying the possibility of producing and detecting it in Large Hadron Collider. Assuming WIMPs being the maverick particle within collider, it is …
A dark Z is a massive Abelian gauge boson which is coupled to the Standard Model through both kinetic and mass mixing with the electroweak sector. We study the phenomenology of the dark Z at an energy-frontier electron-positron collider, such as the proposed International Linear Collider (ILC). We show that precision electroweak constraints and the current bounds from the hadron colliders allow a dark Z that is kinematically accessible at the ILC with 250 GeV or 500 GeV center-of-mass energy. Further, the reach of the ILC searches for a dark Z significantly exceeds the expected reach of the hi…
Dark matter that interacts with the Standard Model by exchanging photons through higher multipole interactions occurs in a wide range of both strongly as well as weakly coupled hidden sector models. We study the collider detection prospects of these candidates, with a focus on Majorana dark matter that couples through the anapole moment. The study is conducted at the effective field theory level with the mono-$Z$ signature incorporating varying levels of systematic uncertainties at the high-luminosity LHC. The projected collider reach on the anapole moment is then compared to the reach coming …
We discuss model-independent collider constraints on the effective couplings of leptophilic dark matter (LDM), considering its production at a future electron-positron linear collider, with both polarized and unpolarized beam options, in the mono-photon and mono-$Z$ channels. We show that the future collider constraints are largely complementary to the direct and indirect detection limits on LDM, and can potentially provide the best-ever LDM sensitivity in the low-mass regime (below $\sim$ 10 GeV).
We investigate the possibility of detecting dark matter at TeV scale linear colliders in the scenario where the dark matter is a massive particle weakly interacting only with the Higgs boson $h$ in the low energy effective theory (the Higgs portal dark matter scenario). The dark matter in this scenario would be difficult to be tested at the CERN Large Hadron Collider when the decay of the Higgs boson into a dark matter pair is not kinematically allowed. We study whether even in such a case the dark matter $D$ can be explored or not via the $Z$ boson fusion process at the International Linear C…
We investigate the possibility of detecting dark matter at TeV scale linear colliders in the scenario where the dark matter interacts with standard model particles only via the Higgs boson. In this scenario, the dark matter would be difficult to be tested at the LHC especially when the decay of the Higgs boson into a dark matter pair is not kinematically allowed. In this talk, we discuss whether even such a case can be explored or not at the ILC and CLIC via the Z boson fusion process. This talk is mainly based on Phys. Rev. D 82, 055026 (2010) and Phys. Lett. B 701, 591 (2011).
The lightest neutralino in supersymmetric models with conserved R-parity is an attractive candidate for non-luminous matter in the universe. If relic neutralinos are indeed present as dark matter in our galaxy, they can be directly detected in scattering experiments. This could serve as an independent search channel for supersymmetry complementary to collider experiments. I compare the sensitivity of direct detection experiments with the reach for supersymmetry at collider facilities in the framework of the minimal supergravity model.
Dark matter pair production at high energy colliders may leave observable signatures in the energy and momentum spectra of the objects recoiling against the dark matter. We discuss signatures of Dark Matter in the jets + missing energy and photon + missing energy channels at the Tevatron and at LEP. Working in a largely model-independent effective theory framework, we can convert the collider bounds into constraints on the dark matter-nucleon scattering cross section and on the dark matter annihilation cross section. Our bounds are highly competitive with those from direct and indirect dark ma…
Searches for Dark Matter at the LHC are commonly described in terms of simplified models with scalar, pseudo-scalar, vector and axial-vector mediators. In this work we explore the constraints imposed on such models from the observed Dark Matter relic abundance. We present these constraints over a range of mediator masses relevant for the LHC and for future, higher energy colliders. We additionally compute bounds from a photon line search for the decay of a pseudo-scalar mediator to di-photons that includes the mediator mass region near 750 GeV. Finally, we compare cosmological constraints with…
We investigate a dark matter model involving an inert $\mathrm{SU}(2)_\mathrm{L}$ quadruplet scalar with hypercharge 1/2. After the electroweak symmetry breaking, the dark sector contains one doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar can be a viable dark matter candidate. Electroweak production of these scalars at the Large Hadron Collider leads to potential signals in the $\text{monojet} + /\!\!\!\!E_\mathrm{T}$ and $\text{soft-leptons} + \text{jets} + /\!\!\!\!E_\mathrm{T}$ channels. We thus derive constraints on the model by reinterpreting recen…
We consider the possibility that the dark matter particle is a scalar WIMP messenger associated to neutrino mass generation, made stable by the same symmetry responsible for the radiative origin of neutrino mass. We focus on some of the implications of this proposal as realized within the singlet-triplet scotogenic dark matter model.We identify consistent parameter sets consistent both with neutrino mass and the observed dark matter abundance. Finally we characterize the expected phenomenological profile of heavy Higgs boson physics at the LHC as well as at future linear Colliders.
Recent data on $e^+/e^-$ and $\bar{p}$ cosmic rays suggest that dark matter annihilate into the standard model (SM) particles through new leptophilic interaction. In this paper, we consider a standard model extension with the gauged $U(1)_{L_μ- L_τ}$ group, with a new Dirac fermion charged under this U(1) as a dark matter. We study the muon $(g-2)_μ$, thermal relic density of the cold dark matter, and the collider signatures of this model. $Z^{'}$ productions at the Tevatron or the LHC could be easily order of $O(1)-O(10^3)$ fb.
We add fermions to an abelian-gauged hidden sector. We show that the lightest can be the dark matter with the right thermal relic abundance, and discovery is within reach of upcoming dark matter detectors. We also show that these fermions change Higgs boson phenomenology at the Large Hadron Collider (LHC), and in particular could induce a large invisible width to the lightest Higgs boson state. Such an invisibly decaying Higgs boson can be discovered with good significance in the vector boson fusion channel at the LHC.
The lightest superparticle in the MSSM is expected to be a Bino, Higgsino or Wino. We consider the dark matter abundance constraint on these LSP scenarios in the minimal SUGRA and AMSB models. We discuss the resulting collider signals for the Bino LSP at LHC and the Higgsino and Wino LSP at CLIC. The Bino, Higgsino and Wino LSP signals in dark matter experiments are also discussed briefly. We conclude with a discussion of these LSP scenarios in nonminimal SUSY models.
Decays of sneutrinos are considered in the case that in the presence of lepton-number violation in the sneutrino sector the lighter tau-sneutrino is the Lightest Supersymmetric Particle and the Cold Dark Matter in the Universe. In such circumstances the signals from sparticle decays differ considerably from the ``standard'' case where the lightest neutralino is the Lightest Supersymmetric Particle and it is found that in a wide range of parameters compatible with the sneutrino Cold Dark Matter hypothesis signatures characteristic for such a scenario should be easily observable at for example a…
We consider the capability of the e^+e^- linear collider (which is recently called as the International Linear Collider, or ILC) for studying the properties of the heavy Higgs bosons in the supersymmetric standard model. We pay special attention to the large \tanβregion which is motivated, in particular, by explaining the dark-matter density of the universe (i.e., so-called ``rapid-annihilation funnels''). We perform a systematic analysis to estimate expected uncertainties in the masses and widths of the heavy Higgs bosons assuming an energy and integrated luminosity of \sqrt{s}=1 TeV and L=1 …
This talk presents the detection issues for the lightest slepton \tildeτ_1 at a future e+e- TeV collider given the dark matter constraints set on the SUSY mass spectrum by the WMAP results. Two methods for measuring its mass m_{\tildeτ_1} and the resulting precision on the dark matter density are briefly discussed in the SUSY mSUGRA scenario with R-parity conservation when the mass difference between m_{\tildeτ_1} and that of the lightest neutralino is small (a few GeV). The analysis is performed with TESLA parameters in both head-on and crossing angle modes.
The Inert Doublet Model(IDM) is one of the simplest extensions beyond Standard Model(SM) with an extended scalar sector, which provide a scalar dark matter particle candidate. In this paper, we investigate the double charged Higgs production at $γγ$ collider. By scanning the whole parameter space, we obtain the parameter points corresponding to the correct relic abundance of dark matter. After applying all theoretical and experimental constraints, the parameter space for the existence of dark matter is extremely restricted. We perform the analysis for the signal of $H^+H^-$ production in the I…
We evaluate the prospects for finding evidence of dark matter production at the Large Hadron Collider. We consider WIMPs and superWIMPs, weakly- and superweakly-interacting massive particles, and characterize their properties through model-independent parameterizations. The observed relic density then implies lower bounds on dark matter production rates as functions of a few parameters. For WIMPs, the resulting signal is indistinguishable from background. For superWIMPs, however, this analysis implies significant production of metastable charged particles. For natural parameters, these rates m…
We investigate the signatures at the Large Hadron Collider of a minimal model where the dark matter particle is a Majorana fermion that couples to the Standard Model via one or several coloured mediators. We emphasize the importance of the production channel of coloured scalars through the exchange of a dark matter particle in the t-channel, and perform a dedicated analysis of searches for jets and missing energy for this model. We find that the collider constraints are highly competitive compared to direct detection, and can even be considerably stronger over a wide range of parameters. We al…
We study a dark matter model constructed by extending the standard model with an inert $\mathrm{SU}(2)_\mathrm{L}$ sextuplet scalar of hypercharge 1/2. The sextuplet components are split by the quartic couplings between the sextuplet and the Higgs doublet after electroweak symmetry breaking, resulting in a dark sector with one triply charged, two doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar boson acts as a dark matter particle. We investigate the constraints on this model from the $\text{monojet} + /\!\!\!\!E_\mathrm{T}$ and $\text{soft-dilepton} + \t…
If future colliders discover supersymmetric particles and probe their properties, one could predict the dark matter density of the Universe and would constrain cosmology with the help of precision data provided by WMAP and PLANCK. We investigate how well the relic density can be predicted in minimal supergravity (mSUGRA), with and without the assumption of mSUGRA when analysing data. We determine the parameters to which the relic density is most sensitive, and quantify the collider accuracy needed. Theoretical errors in the prediction are investigated in some detail.
These lectures give an overview of aspects of missing E_T signatures from new physics at the LHC, along with their important connection to dark matter physics. Mostly, I will concentrate on supersymmetric (SUSY) sources of missing E_T, but will also mention Little Higgs models with T-parity (LHT) and universal extra dimensions (UED) models with KK-parity. Lecture 1 covers SUSY basics, model building and spectra computation. Lecture 2 addresses sparticle production and decay mechanisms at hadron colliders and event generation. Lecture 3 covers SUSY signatures at LHC, along with LHT and UED sign…
We examine lepton flavor violating (LFV) interactions for heavy right-handed neutrinos that exist in most of the standard model extensions that address dark matter (DM) and neutrino mass at the loop level. In order to probe the collider effect of these LFV interactions, we impose the assumption that the model parameters give the right values of the DM relic density and fulfill the constraints from the LFV processes $\ell_α\rightarrow\ell_βγ$ and $\ell_α\rightarrow3\ell_β$. We also investigate the possibility of probing these interactions, and hence the right-handed neutrino, at leptonic collid…
We explore the mono-$Z$ signature for dark matter searches at future high energy $e^+e^-$ colliders. In the context of effective field theory, we consider two kinds of contact operators describing dark matter interactions with electroweak gauge bosons and with electron/positron, respectively. For five benchmark models, we propose kinematic cuts to distinguish signals from backgrounds for both charged leptonic and hadronic decay modes of the $Z$ boson. We also present the experimental sensitivity to cutoff scales of effective operators and compare it with that of the Fermi-LAT indirect search a…
