We investigate the possibility of the identification of TeV physics models including WIMP dark matter at the International Linear Collider. Many TeV physics models contain a WIMP dark matter (chi^0) and charged new particle (chi^{pm}) which interacts with the WIMP dark matter via the vertex chi^{pm} chi^0 W^{mp}. Through Monte Carlo simulations, we study the process, e^+e^- to chi^+ chi^- to chi^0 chi^0 W^+ W^-, because the signal contains the fruitful information of the model. We show that, in particular, the distribution of the chi^{pm} production angle is the powerful probe in the TeV physics model search.
We study the possibility of identifying dark matter properties from XENON-like 100 kg experiments and the GLAST satellite mission. We show that whereas direct detection experiments will probe efficiently light WIMPs, given a positive detection (at the 10% level for $m_χ \lesssim 50$ GeV), GLAST will be able to confirm and even increase the precision in the case of a NFW profile, for a WIMP-nucleon cross-section $σ_{χ-p} \lesssim 10^{-8}$ pb. We also predict the rate of production of a WIMP in the next generation of colliders (ILC), and compare their sensitivity to the WIMP mass with the XENON …
In this study, the sensitivity of future lepton colliders to WIMP dark matter is evaluated assuming WIMP pair production accompanied by a photon from initial state radiation, through which the process can be identified. A full detector simulation for the International Large Detector (ILD) concept at the International Linear Collider (ILC) is performed for a \com energy of 500\,GeV. Energy scales of up to $3$\,TeV can be tested for different effective operators for WIMP masses almost up to half the \com energy. The sensitivity benefits from the polarised beams, which can reduce the main SM back…
The WIMP (weakly interacting massive particle) paradigm for dark matter is currently being probed via many different experiments. Direct detection, indirect detection and collider searches are all hoping to catch a glimpse of these elusive particles. Here, we examine the potential of the ILC (International Linear Collider) to shed light on the origin of dark matter. By using an effective field theory approach we are also able to compare the reach of the ILC with that of the other searches. We find that for low mass dark matter (< 10 GeV), the ILC offers a unique opportunity to search for WIMPS…
A Weakly Interacting Massive Particle (WIMP) provides an attractive dark matter candidate, and should be within reach of the next generation of high-energy colliders. We consider the process of direct WIMP pair-production, accompanied by an initial-state radiation photon, in electron-positron collisions at the proposed International Linear Collider (ILC). We present a parametrization of the differential cross section for this process which conveniently separates the model-independent information provided by cosmology from the model-dependent inputs from particle physics. As an application, we …
If the cold dark matter consists of weakly interacting massive particles (WIMPs), anticipated measurements of the WIMP properties at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) will provide an unprecedented experimental probe of cosmology at temperatures of order 1 GeV. It is worth emphasizing that the expected outcome of these tests may or may not be consistent with the picture of standard cosmology. For example, in kination-dominated quintessence models of dark energy, the dark matter relic abundance can be significantly enhanced compared to that obtained from…
High energy colliders provide a new unique way to determine the microscopic properties of the dark matter (DM). Weakly interacting massive particles (WIMPs) are widely considered as one of the best DM candidates. It is usually assumed that the WIMP couples to the SM sector through its interactions with quarks and leptons. In this paper, we investigate the DM pair production associated with a $Z$ boson in an effective field theory framework at the International Linear Collider (ILC), which can be used to study the interactions between the DM and leptons. For illustrative purposes, we present th…
We study the possibility of identifying dark matter properties from direct (XENON100) and indirect (GLAST) detection experiments. In the same way, we examine the perspectives given by the next generation of colliders (ILC). All this analysis is done following a model-independent approach. We have shown that the three detection techniques can act in a highly complementary way. whereas direct detection experiments will probe efficiently light WIMPs, given a positive detection (at the 10% level for $m_χ \sim 50$ GeV), GLAST will be able to confirm and even increase the precision in the case of a …
Weakly interacting massive particles (WIMPs) form a promising solution to the dark matter problem and many experiments are now searching for these particles. Using effective field theories to describe the interaction of the WIMP with the Standard Model has proven successful in providing an easy way to compare the different experimental results. In this work, we show how effective operators can be formally derived from a UV-complete underlying theory, and we analyse these operators in different experimental contexts. We put our main focus on the expected sensitivity of the International Linear …
The International Linear Collider (ILC) has recently proven its technical maturity with the publication of a Technical Design Report, and there is a strong interest in Japan to host such a machine. We summarize key aspects of the Beyond the Standard Model physics case for the ILC in this contribution to the US High Energy Physics strategy process. On top of the strong guaranteed physics case in the detailed exploration of the recently discovered Higgs boson, the top quark and electroweak precision measurements, the ILC will offer unique opportunities which are complementary to the LHC program …
The large hadron collider (LHC) is anticipated to provide signals of new physics at the TeV scale, which are likely to involve production of a WIMP dark matter candidate. The international linear collider (ILC) is to sort out these signals and lead us to some viable model of the new physics at the TeV scale. In this article, we discuss how the ILC can discriminate new physics models, taking the following three examples: the inert Higgs model, the supersymmetric model, and the littlest Higgs model with T-parity. These models predict dark matter particles with different spins, 0, 1/2, and 1, res…
Non-standard scenarios described by effective contactlike interactions can be revealed only by searching for deviations of the measured observables from the Standard Model (SM) predictions. If deviations were indeed observed within the experimental uncertainty, the identification of their source among the different non-standard interactions should be needed. We here consider the example of the discrimination of gravity in compactified extra dimensions (ADD model) against the four-fermion contact interactions (CI). We present assessments of the identification reach on this scenario, that could …
Deviations from the standard Higgs sector generated by some new physics at an energy scale $Λ$ could be described by an effective $SU(3)_c \times SU(2)_L \times U(1)$ invariant non-renormalizable Lagrangian terms of dimension six. A systematic study of various Higgs boson production channels ($γγ$, $ZZ$, $WW$, $b \bar b$, $τ\bar τ$) at the International Linear Collider (ILC) in the SM extension by effective operators is carried out. Statistical methods are used to establish a degree of consistency for the standard Higgs sector with the forthcoming data, using the expected ILC accuracies of the…
In this paper, we introduce model-independent data analysis procedures for identifying inelastic WIMP-nucleus scattering as well as for reconstructing the mass and the mass splitting of inelastic WIMPs simultaneously and separately. Our simulations show that, with O(50) observed WIMP signals from one experiment, one could already distinguish the inelastic WIMP scattering scenarios from the elastic one. By combining two or more data sets with positive signals, the WIMP mass and the mass splitting could even be reconstructed with statistical uncertainties of less than a factor of two.
One of the highest priorities in particle physics today is the identification of the constituents of dark matter. This manuscript is a supplement to pedagogical lectures given at the 2021 Les Houches Summer School on Dark Matter. The lectures cover topics related to the direct detection of WIMP dark matter, including the distribution of dark matter, nuclear scattering, backgrounds, planning and designing of experiments and a sampling of planned and ongoing experiments.
In the Littlest Higgs model with T-parity, the heavy photon ($A_{H}$) is supposed to be a possible dark matter (DM) candidate. A direct proof of validity of the model is to produce the heavy photon at accelerator. In this paper, we study the production rate of $ e^ + e^ - \to A_{H}A_{H}$ at the international $e^ + e^ -$ linear collider (ILC) in the Littlest Higgs model with T-parity and show the distributions of the transverse momenta of $A_{H}$. The numerical results indicate that the heavy photon production rate could reach the level of $10^{-1} fb$ at some parameter space, so it can be a go…
We describe DSiD, a fast simulation Delphes detector for the International Linear Collider (ILC) based on the full simulation performance of the SiD detector. SiD is one of two detectors described in the ILC Technical Design Report (TDR). The tracking efficiency, tracking momentum resolution, electromagnetic and hadronic calorimeter energy resolution, particle identification and flavor tagging efficiencies are taken from the Detailed Baseline Design (DBD) study as described in ILC TDR Volume 4: Detectors. In a cross-check study with $4 \times 10^6$ $e^+ e^- \rightarrow b \bar{b}$ events genera…
Identification of beyond-standard-models including WIMP dark matter is studied in four particle final state with a W boson pair and a WIMP pair at the International Linear Collider. Models with different spin structures give distinguishable production angle distributions. After the mass determination in each model, the production angle is reconstructed using the four momentum of W bosons with a back-to-back constraint. Three models of Inert Higgs, Supersymmetry and Little Higgs are considered. Discrimination power at 200 fb and 40 fb signal cross section with 500 fb-1 luminosity at sqrt(s) = 5…
We study the prospects for detecting Weakly Interacting Massive Particles (WIMPs), in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that in case of detection, comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly m…
Non-standard scenarios described by effective interactions can manifest themselves indirectly, via corrections to the Standard Model cross sections. It should be desirable to identify at a given confidence level the source of such deviations among the different possible explanations. We here discuss the identification reach on gravity in extra dimensions from the four-fermion compositeness-inspired contact interactions and viceversa, using as basic observable the differential cross section of $e^+e^-\to\bar{f}f$ at the ILC, and emphasize the role of beams polarization in enhancing the identifi…
Numerous non-standard dynamics are described by contact-like effective interactions that can manifest themselves in electron-positron collisions only through deviations of the observables (cross sections, asymmetries) from the Standard Model predictions. If such a deviation were observed, it would be important to identify the actual source among the possible non-standard interactions as many different new physics scenarios may lead to very similar experimental signatures. We study the possibility of uniquely identifying the indirect effects of s-channel sneutrino exchange, as predicted by supe…
Spin identification of the mono-Z$^{\prime}$ resonance in muon-pair production at the ILC with simulated electron-positron collisions at $\sqrt{s}$ = 500 GeV
Centre for Theoretical Physics, The British University in Egypt（埃及英国大学理论物理中心）
We assess the prospects for indirect detection of Weakly Interacting Massive Particles using a large Liquid Argon TPC detector. Signal events will consist of energetic electron (anti)neutrinos coming from the decay of $τ$ leptons and $b$ quarks produced in WIMP annihilation in the core of the Sun. Background contamination from atmospheric neutrinos is expected to be low, thanks to the superb angular resolution and particle identification capabilities provided by the considered experimental set-up. We evaluate the event rates predicted for an annihilating WIMP as a function of its elastic scatt…
The search for and potential identification of dark matter (DM) will require a simultaneous, multi-pronged approach with important roles to be played by the LHC, both direct and indirect DM detection experiments and, eventually, the ILC. The 19-parameter p(henomenological)MSSM can provide a broad framework for complementarity studies of neutralino DM. In this talk, I summarized the sensitivity of these searches at the 7, 8 and 14 TeV LHC, combined with those from \Fermi, CTA, IceCube/DeepCore, COUPP, LZ and XENON. The strengths and weaknesses of each of these searches is briefly discussed as i…
A recently proposed dark matter WIMP has only second-order couplings to gauge bosons and itself. As a result, it has small annihilation, scattering, and creation cross-sections, and is consequently consistent with all current experiments and the observed abundance of dark matter. These cross-sections are, however, still sufficiently large to enable detection in experiments that are planned for the near future, and definitive identification in experiments proposed on a longer time scale. The (multi-channel) cross-section for annihilation is consistent with thermal production and freeze-out in t…
The strong CP problem of QCD is at heart a problem of naturalness: why is the F\tilde{F} term highly suppressed in the QCD Lagrangian when it seems necessary to explain why there are three and not four light pions? The most elegant solution posits a spontaneously broken Peccei-Quinn (PQ) symmetry which requires the existence of the axion field a. The axion field settles to the minimum of its potential thus removing the offensive term but giving rise to the physical axion whose coherent oscillations can make up the cold dark matter. Only now are experiments such as ADMX beginning to explore QCD…
New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W^\pm-pair production cross sections at the e^+e^- International Linear Collider (ILC), especially as regards the potential of distinguishin…
Imposing electroweak scale naturalness constraints (low Δ_{EW}) on SUSY models leads to mass spectra characterized by light higgsinos ~100-300 GeV, highly mixed top-squarks and gluinos at the 1-5 TeV scale and allows for m_h ~125 GeV. First and second generation squarks can easily live at the 5-20 TeV scale, thus providing at least a partial solution to the SUSY flavor/CP problems. For such models at the LHC, gluino pair production is followed by cascade decays to t- and b-quark rich final states along with multileptons. The reach of LHC14 with 300 fb^{-1} is computed to be around m_{\tg} 1.8 …
One of the most puzzling problems of modern physics is the identification of the nature a non-relativistic matter component present in the universe, contributing to more than 25$\%$ of the total energy budget, known as Dark Matter. Weakly Interacting Massive Particles (WIMPs) are among the best motivated dark matter candidates. However, in light of non conclusive detection signals and strong constraints from collider, direct and indirect detection experiments, this thesis presents constraints on several realizations of the WIMP paradigm in the context of simplified dark matter models. More ela…
Dark matter (DM) is currently searched for with a variety of detection strategies. Accelerator searches are particularly promising, but even if Weakly Interacting Massive Particles (WIMPs) are found at the Large Hadron Collider (LHC), it will be difficult to prove that they constitute the bulk of the DM in the Universe. We show that a significantly better reconstruction of the DM properties can be obtained with a combined analysis of LHC and direct detection (DD) data, by making a simple Ansatz on the WIMP local density, i.e. by assuming that the local density scales with the cosmological reli…
Operator Identification in Charged Lepton-Flavor Violation: Global EFT Analysis with RG Evolution, Polarization Observables, and Bayesian Model Discrimination at Future Colliders
Universidad Técnica Federico Santa María（弗雷德里克·萨马利亚技术大学）；Millennium Institute for Subatomic Physics at the High-Energy Frontier (SAPHIR)（高能前沿亚原子物理千年研究所（SAPHIR））
Weakly interacting massive particles (WIMPs) and strangelets are two classes of "exotic" particles not yet discovered, and in agreement with theoretical scenarios most probably produced in different early stages of evolution of the Universe. Some peculiarities of their energy loss in the electronic and nuclear interactions with ordinary matter are investigated. For the direct detection of WIMPs the signals produced by the stopping of recoils in matter are used for their identification. The influence of the orientation of the recoil in respect to crystal axes for crystalline silicon (as materia…
We study an effective theory beyond the standard model (SM) where either of two additional gauge singlets, a Majorana fermion and a real scalar, constitutes all or some fraction of dark matter. In particular, we focus on the masses of the two singlets in the range of O(10) MeV-O(10) GeV, with a neutrino portal interaction which plays important roles not only in particle physics but also in cosmology and astronomy. We point out that the dark matter abundance can be thermally explained with (co)annihilation, where the dark matter with a mass greater than 2 GeV can be tested in future lepton coll…
The proposed International Linear Collider (ILC) is well-suited for discovering physics beyond the Standard Model and for precisely unraveling the structure of the underlying physics. The physics return can be maximized by the use of polarized beams. This report shows the paramount role of polarized beams and summarizes the benefits obtained from polarizing the positron beam, as well as the electron beam. The physics case for this option is illustrated explicitly by analyzing reference reactions in different physics scenarios. The results show that positron polarization, combined with the clea…
Future dark matter (DM) direct detection searches will be subject to irreducible neutrino backgrounds that will challenge the identification of an actual WIMP signal in experiments without directionality sensitivity. We study the impact of neutrino-quark non-standard interactions (NSI) on this background, assuming the constraints from neutrino oscillations and the recent COHERENT experiment data, which are relevant for NSI mediated by light mediators, $m_{\rm med} \lesssim{\cal O}$(GeV). We calculate the expected number of neutrino-nucleus elastic scattering events in a Xe-based ton-size dark …
As is well known, the search for and eventual identification of dark matter in supersymmetry requires a simultaneous, multi-pronged approach with important roles played by the LHC as well as both direct and indirect dark matter detection experiments. We examine the capabilities of these approaches in the 19-parameter p(henomenological)MSSM which provides a general framework for complementarity studies of neutralino dark matter. We summarize the sensitivity of dark matter searches at the 7, 8 (and eventually 14) TeV LHC, combined with those by \Fermi, CTA, IceCube/DeepCore, COUPP, LZ and XENON.…
Weakly interacting massive particles (WIMPs) remain a prime candidate for the cosmological dark matter (DM), even in the absence of current collider signals that would unambiguously point to new physics below the TeV scale. The self-annihilation of these particles in astronomical targets may leave observable imprints in cosmic rays of various kinds. In this review, we focus on gamma rays which we argue to play a pronounced role among the various possible messengers. We discuss the most promising spectral and spatial signatures to look for, give an update on the current state of gamma-ray searc…
Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) searched for astroparticle dark matter using superheated liquid C$_{2}$ClF$_{5}$ droplet detectors. Each droplet generally requires an energy deposition with linear energy transfer (LET) $\gtrsim$ 150 keV/$μ$m for a liquid-to-gas phase transition, providing an intrinsic rejection against minimum ionizing particles of order 10$^{-10}$, and reducing the backgrounds to primarily $α$ and neutron-induced recoil events. The droplet phase transition generates a millimetric-sized gas bubble which is recorded by acoustic means…
