Search for the lightest chargino at s**(1/2) = 130-GeV and 136-GeV in DELPHI

Abreu, P. [--] Cortina Gil, Eduardo [UCL] DELPHI Collaboration [--] et al.

A search for pair production of the lightest chargino at View the MathML source GeV has been carried out using the data sample corresponding to the 5.92 pb−1 recorded by the DELPHI detector during the high energy run of LEP in the last period of 1995. The theoretical reference model has been the Minimal Supersymmetric Standard Model with R-parity conservation. The three topologies expected for the decay of a pair of charginos, namely two acoplanar leptons plus missing energy (ℓℓ), two jets and an isolated lepton plus missing energy (jjℓ) and missing energy in a hadronic environment (View the MathML source), were investigated. No evidence of a signal was found. Lower mass limits were derived for various scenarios, including the case of a low mass difference between the chargino and the neutralino and of a light sneutrino. The mass limits range between 56.3 GeV/c2 and the kinematic limit.