Related papers: Excited Leptonic States in Polarized e^-\gamma and…
We explore the use of polarized $e^+/e^-$ beams and/or the information on final state decay lepton polarizations in probing the interaction of the Higgs boson with a pair of vector bosons. A model independent analysis of the process $e^+…
This work aims to study theoretically the electron-proton scattering for initially spin-polarized electrons in the presence of a circularly polarized electromagnetic field. Using the first Born approximation and the Dirac-Volkov states for…
The experimental observables for the elastic reaction induced by protons on electrons are calculated in the Born approximation. Model independent expressions are derived for the differential cross section and polarization observables.…
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…
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…
We have searched for unstable neutral and charged heavy leptons, N and L^+/-, and for excited states of neutral and charged leptons, nu*, e*, mu* and tau*, in e^+e^- collisions at centre-of-mass energies of 170 and 172 GeV using the OPAL…
A polarized $ep/eA$ collider (Electron--Ion Collider, or EIC), with polarized proton and light-ion beams and unpolarized heavy-ion beams with a variable center--of--mass energy $\sqrt{s} \sim 20$ to $\sim100$~GeV (upgradable to $\sim 150$…
We show that the accumulated LEP-II data taken at $\sqrt{s} =$ 130 to 206 GeV can establish more restrictive bounds on doubly charged bileptons couplings and masses than any other experiment so far. We also analyze the discovery potential…
New insights into our understanding of the semirelativistic excitation of atomic hydrogen by electronic impact have been made possible by combining the use of polarized electron beams and intense laser field. The paper reviews relativistic…
We investigate the Lepton Flavor Violating (LFV) process $e^{+}e^{-}\to e^{+}e^{-}e\mu$ ($e=e^-,\,e^+,\,\mu=\mu^-,\,\mu^+ $) at future circular colliders, probing the effective $\gamma\gamma e\mu$ interaction through photon fusion. Within…
The excitation of the carbon $2^+$ state at 4.439 MeV by $70-150$ MeV electron impact and its subsequent decay to the ground state by photon emission is described within the distorted-wave Born approximation. The transition densities are…
There exists a world--wide consensus for a future $e^+e^-$ Linear Collider in the energy range between $\sqrt{s}=500--1000$ GeV as the next large facility in HEP. The Linear Collider has a large physics potential for the discovery of new…
We examine the production of an invisible state $X$ together with a photon, $e^+e^- \to \gamma +X$, at electron positron colliders and present measurement strategies that can detect the spin of the invisible state as well as the underlying…
We study anomalous $W^-W^+Z/\gamma$ couplings due to dimension-$6$ operators in the production process $e^-e^+ \to W^-W^+$ followed by semi-leptonic decay using polarizations and spin-spin correlations of $W$ bosons. The construction of…
Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly in future $e^+ e^-$ collider experiments with polarized…
Quantum entanglement is a cornerstone of quantum mechanics. While the entanglement of confined electron pairs has been established early on, the entanglement of free-traveling electron pairs, particularly at high energies, remains largely…
We consider the possibility of observing deviations from the Standard Model gauge-boson self-couplings at future $e\gamma$ colliders. We concentrate on the process $e^-\gamma \rightarrow \nu W^- Z$, which is particularly sensitive to the…
Manifestation of the heavy 3/2-spin lepton $(h^\pm)$, as possible virtual intermediate state in Feynmann diagrams, have been searched in the $e^+\,e^-\to \gamma\,\gamma$ reaction at high energies and large photon angles. The spin-vector…
I review the physics capabilities of the machines proposed for the next generation of high-energy experimentation: in hadron physics, the LHC, and in electron physics, a $500$--$1500$ GeV $e^+e^-$ linear collider. Using for illustration two…
We describe how to probe new physics through examination of the form factors describing the Ztt couplings via the scattering process e^-e^+->t+tbar. We focus on experimental methods on how the top quark momentum can be determined and show…