Related papers: Single-photon signal from neutralinos at LEP2
Supersymmetry (SUSY) is a theory that gives an explanation for the strong and electroweak interactions from the grand unification scale down to the weak scale. The search for supersymmetric particles still continues at full speed at the LHC…
It is shown how the fundamental gaugino and higgsino parameters of the chargino and neutralino system in the MSSM can completely be determined in high--precision experiments at e+e- linear colliders even if in their initial phase only the…
We examine various predictions of the minimal supersymmetric standard model coupled to minimal supergravity. The model is characterised by a small set of parameters at the unification scale. The supersymmetric particle spectrum at low…
In most supersymmetric theories charginos, $\tilde{\chi}^\pm_{1,2}$, belong to the class of the lightest supersymmetric particles. The chargino system can be reconstructed completely in $e^+e^-$ collider experiments:…
We investigate a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. For this the Minimal Supersymmetric Standard Model is extended by adding light right-handed neutrinos and…
We study the impact of beam polarization on radiative neutralino production e+e- \to \chi^0_1 \chi^0_1 photon at the International Linear Collider. We show that longitudinal polarized beams significantly enhance the signal and…
Motivated by the recent re-confirmation by CoGENT of the low-energy excess of events observed last year, and the recent improved limits from the XENON-100 experiment that are in contention with the CoGENT data, we re-examine the low mass…
We study how the properties of the four neutralino states, chi_i (i = 1, 2, 3, 4), can be investigated at the Large Hadron Collider (LHC), in the case when the lightest one, chi_1, has a mass m_chi < 50 GeV and is stable. This situation…
We present a high precision calculation of chargino and neutralino pair production at $e^+e^-$ colliders. Within the Minimal Supersymmetric Standard Model, the full one-loop and higher order QED corrections are included. Special care has…
We discuss a potential of studying the production and the decay of the lightest top squark (t-tilde_1) in the framework of the supersymmetric standard model at a future e^+e^- collider. In particular, we consider the process t-tilde_1 -> t…
The chargino and neutralino pair production processes at $e^+e^-$ collisions are explored to determine the underlying SUSY parameters. The sum rules for the couplings are used to check the closure of two-chargino and four-neutralino systems…
Searches for final states expected in models with light gravitinos have been performed, including experimental topologies with multi-leptons with missing energy, leptons and photons with missing energy, and jets and photons with missing…
The multi-sector SUSY breaking predicts the existence of pseudo-goldstino, which could couple more strongly to visible fields than ordinary gravitino. Then the lightest neutralino and chargino can decay into a pseudo-goldstino plus a…
We study the neutralino mass spectra and production cross sections at an e^+e^- linear collider in superstring-inspired E_6 models. These models are characterized by the existence of new neutral gauge bosons and singlet Higgs fields which…
We report the result of a search for charginos and neutralinos, in e+e- collisions at 189 GeV centre-of-mass energy at LEP. No evidence for such particles is found in a data sample of 176 pb^{-1}. Improved upper limits for these particles…
We analyze the accelerator constraints on the parameter space of the Minimal Supersymmetric extension of the Standard Model, comparing those now available from LEP II and anticipating the likely sensitivity of Tevatron Run II. The most…
Naturalness arguments imply the existence of higgsinos lighter than 200-300 GeV. However, because these higgsinos are nearly mass degenerate, they release very little visible energy in their decays, and signals from electroweak higgsino…
High statistics Standard Model processes like fermion- and photon-pair production in e+e- collisions are studied at centre-of-mass energies up to 209 GeV. No significant deviation from the Standard Model is observed, leading to strong…
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair and photon-pair production in e+e- collisions on the full LEP2 data set. The details of the experimental measurements and…
For points in SUSY parameter space where the sneutrino is lighter than the lightest chargino and next-to-lightest neutralino, its direct mass determination from sneutrino pair production process at e+e- collider is impossible since it…