Search for Supersymmetry with Gauge-Mediated Breaking in Diphoton Events at D0

TL;DR

This paper reports a search for gauge-mediated supersymmetry breaking in diphoton events at the D0 experiment, setting new lower mass limits for neutralino and chargino particles with no observed excess over standard model backgrounds.

Contribution

First search for gauge-mediated SUSY breaking in diphoton events at D0, establishing the most stringent mass limits to date for certain SUSY models.

Findings

No excess observed above background

Lower mass limits of ~108 GeV for neutralino

Lower mass limits of ~195 GeV for chargino

Abstract

We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb$^{-1}$ of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002--2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-lightest SUSY particle.