Related papers: Detecting interactions between dark matter and pho…
In this work we study the production of color-neutral and singly-charged heavy leptons at the proposed International Linear Collider. We use the optimal observable technique to determine the statistical accuracy to which the coupling of…
The physics potential is briefly summarized for an e+e- linear collider operating at center-of-mass energies up to \sqrt{s} = 1 TeV and delivering integrated luminosities up to \int L = 0.5 ab^(-1) in one to two years. This machine will…
Up to now, almost all discussion of supersymmetry at future colliders has been concerned with particle searches. However, if candidates for supersymmetric particles are found, there is much more that we will want to know about them.…
We consider production of a e^+e^- pair by a high-energy photon in the field of a strong laser wave. A probability of this process for circularly or linearly polarized laser photons and for arbitrary polarization of all other particles is…
We propose further tests of the assumption that the mass of the heavy standard particles ($Z,W,t,...$) arises from a special coupling with dark matter. We look for effects of new interactions due to dark matter exchanges between heavy…
The production of single- and multi-photon events has been studied in the reaction e+e- -> gamma (gamma) + invisible particles. The data collected with the DELPHI detector during the years 1999 and 2000 at centre-of-mass energies between…
We infer dark matter properties from gamma ray residuals extracted using eight different interstellar emission scenarios proposed by the Fermi-LAT Collaboration to explain the Galactic Center gamma ray excess. Adopting the most plausible…
The discovery potential for detecting new heavy Majorana and Dirac neutrinos at some recently proposed high energy $e^+e^-$ colliders is discussed. These new particles are suggested by grand unified theories and superstring-inspired models.…
The study of strong symmetry breaking at an e+e linear collider with sqrt(s)=0.5-1.5 TeV is reviewed. It is shown that processes such as e+e- --> nu nubar W+ W-, e+e- --> nu nubar t tbar, and and e+e- --> W+ W- can be used to measure chiral…
The production of $\tau\mu$ pairs in electron-positron collisions offers a powerful probe of lepton flavor violation. In this work, we calculate the $e^+ e^- \to \tau \mu$ cross section within the framework of the Standard Model Effective…
We propose a novel mechanism with two component dark matter models. The subdominant dark matter can thermalize the dominant one in galaxies, and leads to core density profiles. Using ultralight dark photons and $\mathrm{GeV}$-$\mathrm{TeV}$…
We discuss four-fermion contact-interaction searches in the processes e^+e^-\to\mu^+\mu^-, c{\bar c} and b{\bar b} at a future e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with both beams longitudinally polarized. Our…
We investigate the sensitivity of a future high-luminosity $e^-e^+$ collider operating at $\sqrt{s}=250~\text{GeV}$ to CP-violating and CP-conserving anomalous $hVV$ interactions via the Higgsstrahlung process. The effects of new physics…
We study the $ZH$ associated production followed by the Higgs $H\to \gamma \bar{\gamma}$ decay into a photon plus an invisible and massless dark photon, at future high-energy $e^+e^-$ facilities. Large $H\to \gamma \bar{\gamma}$ decay rates…
We analyze the manifestations of new matter particles predicted by models of new physics beyond the Standard Model, at present and future high--energy colliders. We consider both the production of these new particles and some of their…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
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…
We explore the properties of self-conjugate dark matter (DM) particles that predominantly interact with Standard Model electroweak gauge bosons, using an effective field theory approach. The study emphasizes effective contact interactions,…
Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these…
We study the potential for using $e\gamma$\ collisions produced by backscattered laser photons to investigate WW$\gamma$\ couplings. We present results for Next Linear Collider energies of 500 GeV and 1 TeV. We find that where statistics…