Searches for Supersymmetry in the photon(s) plus missing energy channels at $\sqrt{s}$ = 161 GeV and 172 GeV

TL;DR

This paper reports on searches for supersymmetric particles in photon plus missing energy channels at LEP energies, setting limits on neutralino mass and testing SUSY models against observed data.

Contribution

It provides new experimental limits on neutralino mass and cross sections in photon plus missing energy channels at specific LEP energies, comparing results with SUSY models.

Findings

No significant deviation from Standard Model predictions.

Set a 71 GeV/c^2 lower limit on the neutralino mass.

Established upper limits on anomalous photon production cross sections.

Abstract

Searches for supersymmetric particles in channels with one or more photons and missing energy have been performed with data collected by the ALEPH detector at LEP. The data consist of 11.1 pb-1 at $\sqrt{s} = 161 GeV$, 1.1 pb-1 at 170 GeV and 9.5 pb-1 at 172 GeV. The e+e- -> nunu+photon cross section is measured. The data are in good agreement with predictions based on the Standard Model, and are used to set upper limits on the cross sections for anomalous photon production. These limits are compared to two different SUSY models and used to set limits on the neutralino mass. A limit of 71 GeV/c^2 at 95% C.L. is set on the mass of the lightest neutralino ($\tau_{\chi_{1}^{0}} \leq $ 3 ns) for the gauge-mediated supersymmetry breaking and LNZ models.