Search for Scalar Leptons in e+e- collisions at \sqrt{s}=189 GeV

TL;DR

This paper reports a search for scalar leptons at LEP with no evidence found, leading to new limits on their production cross sections, masses, and exclusion regions within the MSSM framework.

Contribution

It provides the first set of experimental upper limits and exclusion contours for scalar leptons at 189 GeV, improving constraints on supersymmetric models.

Findings

No evidence for scalar leptons was observed.

Set a lower mass limit of 65.5 GeV for the scalar electron.

Derived new exclusion regions in the MSSM parameter space.

Abstract

We report the result of a search for scalar leptons 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 are set on the production cross sections for these new particles. New exclusion contours in the parameter space of the Minimal Supersymmetric Standard Model are derived, as well as new lower limits on the masses of these supersymmetric particles. Under the assumptions of common gaugino and scalar masses at the GUT scale, we set an absolute lower limit on the mass of the lightest scalar electron of 65.5 GeV