Related papers: Supersymmetric analysis and predictions based on t…
Previously, in the context of the minimal supersymmetric standard model (without {\em a priori} assumptions of parameter unification), we studied the constraints on weak-scale SUSY parameters from chargino production at LEP II, using as…
A search for gravitinos produced in ep collisions is performed using the H1 detector at HERA. The data were taken at a centre-of-mass energy of 319 GeV and correspond to an integrated luminosity of 64.3 pb^{-1} for e^+p collisions and 13.5…
In some areas of supersymmetry parameter space, sneutrinos are lighter than the charginos and the next-to-lightest neutralino, and they decay into the invisible neutrino plus lightest-neutralino channel with probability one. In such a…
We investigate the superWIMP scenario in the framework of supersymmetry, in which the lightest supersymmetric particle is a stable gravitino. We consider slepton, sneutrino or neutralino being the next-lightest supersymmetric particle, and…
The negative outcome of gaugino searches at LEP has been one of the most disappointing results for fans of supersymmetric models. In the framework of minimal supersymmetric models with GUT unification assumptions, the combined absence of…
We propose a new set of supersymmetric benchmark scenarios, taking into account the constraints from LEP, b to s gamma, g_mu - 2 and cosmology. We work in the context of the constrained MSSM (CMSSM) with universal soft supersymetry-breaking…
The scenario of light gluinos and light sbottoms was advocated to explain the discrepancy between the measured and theoretical production of $b$ quarks at the Tevatron. This scenario will have model-independent predictions for $Z\to q\bar q…
During the LEP2 operation, the 4 LEP experiments have collected data at centre-of-mass energies up to 209 GeV. Those data have been analysed in the search of charginos, neutralinos and sfermions in the framework of the Minimal…
A search for supersymmetry is performed in events with a single electron or muon in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated…
We consider B3 mSUGRA models where we have one lepton number violating LQD operator at the GUT scale. This can alter the supersymmetric mass spectrum leading to a sneutrino as the lightest supersymmetric particle in a large region of…
The experimental signatures for low energy supersymmetry breaking are presented. The lightest standard model superpartner is unstable and decays to its partner plus a Goldstino, $G$. For a supersymmetry breaking scale below a few 1000 TeV…
A search for direct pair production of supersymmetric top squarks (stop_1) is presented, assuming the stop_1 decays into a top quark and the lightest supersymmetric particle, neutralino_1, and that both top quarks decay to purely hadronic…
We consider the production and decay of selectrons and charginos in $e^-e^-$ collisions. The advantage over usual $e^+e^-$ collisions is the very low level of standard model backgrounds which should make the discovery of selectrons or…
Charginos $\tilde{\chi}^\pm$ and neutralinos $\tilde{\chi}^0$ in supersymmetric theories can be produced copiously at $e^+e^-$ colliders and their properties can be measured with high accuracy. Consecutively to the chargino system, in which…
After reviewing the theoretical, phenomenological and experimental motivations for supersymmetric extensions of the Standard Model, we recall that supersymmetric relics from the Big Bang are expected in models that conserve R parity. We…
Photonic events with large missing energy have been observed in e+e- collisions at a centre-of-mass energy of 189GeV using the OPAL detector at LEP. Results are presented for event topologies consistent with a single photon or with an…
A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 237.4 pb-1 at e+e- centre-of-mass energies of 183 GeV and 189 GeV. The observed numbers of events - 78 at 183 GeV…
Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is…
We extend the constrained minimal supersymmetric model (CMSSM) by adding a right-handed neutrino superfield ($\nu$CMSSM) which decouples close to the GUT scale. We study the effects of a right-handed neutrino on the low energy spectrum and…
Within the framework of the Next-To-Minimal Supersymmetric Standard Model (NMSSM) we study neutralino production $e^+e^- \longrightarrow \tilde{\chi}^0_i \tilde{\chi}^0_j$ ($i,j=1,\ldots ,5$) at center-of-mass energies between 100 and 600…