Experimental Search for Chargino and Neutralino Production in Supersymmetry Models with a Light Gravitino

TL;DR

This paper reports a search for supersymmetric particles, specifically charginos and neutralinos, in high-energy proton-antiproton collisions, setting new mass limits and excluding certain parameter regions within the minimal supersymmetric standard model with a light gravitino.

Contribution

First experimental search for chargino and neutralino production with a light gravitino in proton-antiproton collisions, establishing new exclusion limits and mass bounds.

Findings

No excess events observed beyond Standard Model expectations.

Excluded chargino masses below 150 GeV/c^2.

Excluded neutralino masses below 75 GeV/c^2.

Abstract

We search for inclusive high $E_T$ diphoton events with large missing transverse energy in $p\bar{p}$ collisions at $\sqrt{s}$=1.8 TeV. Such events are expected from pair production of charginos and neutralinos within the framework of the minimal supersymmetric standard model with a light gravitino. No excess of events is observed. In that model, and assuming gaugino mass unification at the GUT scale, we obtain a 95% CL exclusion region in the supersymmetry parameter space and lower mass bounds of 150 GeV/c$^2$ for the lightest chargino and 75 GeV/c$^2$ for the lightest neutralino.