Related papers: Chargino Pair Production at $e^+e^-$ Colliders wit…
In e^+e^- annihilation at \sqrt{s}=10.6 GeV Belle Collaboration found, that J/psi mesons are predominantly produced in association with an extra \bar{c}c pair. The possible mechanisms of J/psi production are discussed and the probability of…
In split supersymmetry, gauginos and Higgsinos are the only supersymmetric particles which are possibly accessible at foreseeable colliders. While the direct experimental searches, such as LEP and Tevatron experiments, gave robust lower…
To establish the Higgs mechanism {\it sui generis} experimentally, the Higgs self-interaction potential must be reconstructed. This task requires the measurement of the trilinear and quadrilinear self-couplings, as predicted in the Standard…
We study the associated production of the A^0 neutral CP-odd Higgs boson with a neutral gauge boson Z in high energy e^+ e^- collisions at the one loop level. We present a detailed discussion for the total cross-section predicted in the…
CP violation in supersymmetry can give rise to rate asymmetries in the decays of supersymmetric particles. In this work we compute the rate asymmetries for the three-body chargino decays \tilde\chi^\pm_2 \to \tilde\chi^\pm_1 HH,…
We analyze the charge-parity (CP) asymmetry in the charged Higgs boson decays to chargino-neutralino pairs, H^- -> chargino_i + neutralino_j. We show first that these modes have a large branching ratio for m_H^- > 600 GeV. We use Cutkosky…
Searches for pair production of squarks, sleptons, charginos, and neutralinos are performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies from 188.6 to 201.6 GeV. No evidence for any such signals is…
Among the possible decay modes of Higgs particles into supersymmetric states, neutralino and chargino decays play a prominent r\^ole. The experimental opportunities of observing such decay modes at LEP2 and at future e+e- linear colliders…
Electroweak scale higgsinos with a nearly degenerate spectrum in supersymmetric models are well-motivated, but generally less constrained at collider experiments as the decay products are often too soft to detect. Initial photon fusions…
The measurements of the two-photon production of the Higgs boson and of $W^{\pm}$ boson pairs in $e^{+}e^{-}$ collisions at the Future Circular Collider (FCC-ee) are investigated. The processes $e^{+}e^{-}\xrightarrow{\gamma…
We study the one-loop effects of charginos and neutralinos on the helicity amplitudes for $\eeww$ in the minimal supersymmetric standard model. The calculation is tested by using two methods. First, the sum rule for the form factors between…
Very precise measurements of masses and cross sections, with errors of <1%, are expected to be achievable with a future linear collider. Such an accuracy gives sensitivity at the level of quantum corrections, which therefore must be…
Assuming that supersymmetry exists well above the weak scale, we derive the full one-loop matching conditions between the SM and the supersymmetric theory, allowing for the possibility of an intermediate Split-SUSY scale. We also compute…
The CP-violating effects in the neutralino sector of the MSSM can be observed in event-counting type experiments, i.e. without the need of exploiting variables sensitive to beam or neutralino polarization. On the other hand, such CP-odd…
Using $e^+e^-$ collision data collected with the BESIII detector at seven energy points ranging from 3.68 to 3.71 GeV and corresponding to an integrated luminosity of $652.1~{\rm pb^{-1}}$, we present an energy-dependent measurement of the…
Several extended supersymmetric models, motivated by either grand unification, or by neutrino mass generation, predict light doubly charged higgsinos. We study the production of a single doubly charged higgsino and its decay channels at the…
We analyze the prospects at a muon collider for measuring chargino masses in the $\mu^+\mu^-\to \tilde{\chi}^+\tilde{\chi}^-$ processes in the threshold region. We find that a measurement of the lightest chargino mass to better than 200 MeV…
Observing the production of the Higgs particle in the $\gamma$-$\gamma$ mode of a linear $e^+e^-$ collider allows for the measurement of the $H\gamma\gamma$ coupling. We point out that for the intermediate Higgs mass range this measurement…
We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $\mu$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet…
We study chargino pair production at LEP II in supersymmetric models with spontaneously broken R-parity. We perform signal and background analyses, showing that a large region of the parameter space of these models can be probed through…