Related papers: Selectron production at an e-e- linear collider wi…
Approximately 438 pb-1 of e+e- data from the OPAL detector, taken with the LEP collider running at centre-of-mass energies of 192-209 Gev, are analyzed to search for evidence of chargino pair production, e+e- -> tilde chi^+_1 tilde chi^-_1,…
We investigate polarization observables in hyperon-nucleon scattering by decomposing scattering amplitudes into spin-space tensors, where each component describes scattering by corresponding spin-dependent interactions, so that…
Intense positron beams can be prepared via electro production with the reaction $e^{-} + e^{-} \rightarrow e^{-}+e^{+}+e^{-}+e^{-}$ due to the availability of high current electron beams. Head on collisions inside of a magnetic field of a…
The measurement of the top quark polarization, sensitive to the electroweak coupling structure, in t-channel single-top production is presented. Events are analyzed corresponding to an integrated luminosity of approximately…
The production and decay of supersymmetric particles is presented. The dependence of the hadro-production cross section for weakly and strongly interacting yields an improvement of derived mass bounds or the measurement of the masses,…
Recent measurements using the CLAS detector at Jefferson Lab of the reactions $\vec\gamma + p \to K^+ + \vec\Lambda$ and $\vec\gamma + p \to K^+ + \vec\Sigma^0$ have been used to extract the spin transfer coefficients $C_x$ and $C_z$ for…
A theoretical investigation of the bound-free electron-positron pair production in relativistic heavy ion collisions is presented. Special attention is paid to the positrons emitted under large angles with respect to the beam direction. The…
Through the simultaneous measurement of the transverse size as a function of longitudinal position, and the longitudinal distribution of luminosity, we are able to measure the $\beta_y^\ast$ (vertical envelope function at the collision…
We demonstrate in a general framework that polarized photons by backscattered laser beams of adjustable frequencies at a TeV linear $e^+e^-$ collider provide us with a very efficient mechanism to probe CP violation in two-photon collisions.…
We present a detailed calculation of the electron-positron production rate using neutrinos in an intense laser field. The computation is done for the process neutrino to neutrino + electron + positron via the neutral channel and within the…
The inclusive production of charged hadrons in the collisions of quasi-real photons e+e- -> e+e- +X has been measured using the OPAL detector at LEP. The data were taken at e+e- centre-of-mass energies from 183 to 209 GeV. The differential…
Non-zero width and Coulomb rescattering effects are analyzed for the pair production of smuons and selectrons near the thresholds in e+ e- and e- e- collisions, respectively. The excitation curves are predicted in a gauge-invariant form.…
Production of the doubly heavy-flavored hadrons ($B_c$ meson, doubly heavy baryons $\Xi_{cc}$, $\Xi_{bc}$, $\Xi_{bb}$, their excited states and antiparticles of them as well) at $e^+e^-$ colliders is investigated under two different…
The CP properties of Higgs bosons can be probed through their s-channel resonance productions via photon-photon collisions by use of circularly and/or linearly polarized backscattered laser photons at a TeV-scale linear e^+ e^- collider.…
At an e-\gamma collider, a selectron \tilde{e}_{L,R} may be produced in association with a (lightest) neutralino \tilde{\chi}_1. Decay of the selectron may be expected to yield a final state with an electron and another \tilde{\chi}_1. If…
We study CP-violating effects in neutralino production and subsequent decay within the Minimal Supersymmetric Standard Model with complex parameters M_1 and mu. The observable we propose is a T-odd asymmetry based on a triple product in…
We perform a comparative study of the reach of future $e^+e^-$ collider options for the scale of non-resonant new physics effects in the top quark sector, phrased in the language of higher-dimensional operators. Our focus is on the…
We discuss the future prospects of heavy neutrino searches at next generation lepton colliders. In particular, we focus on the planned electron-positron colliders, operating in two different beam modes, namely, $e^+e^-$ and $e^-e^-$. In the…
A successful interpretation of the cross sections for elastic and inelastic vector meson production can be made if one assumes the underlying dynamics to be governed by hard partonic subprocesses. Extending these partonic approaches to…
Supersymmetric models provide many new complex phases which lead to CP violating effects in collider experiments. As an example, CP-sensitive triple product asymmetries in neutralino production and subsequent leptonic two-body decays are…