Search for SUSY in the AMSB scenario with the DELPHI detector

TL;DR

This study used DELPHI data from LEP to search for supersymmetry within the AMSB framework, exploring various signatures but finding no evidence, thus setting new constraints on model parameters.

Contribution

First comprehensive search for SUSY in the AMSB scenario at LEP, covering multiple signatures and establishing new limits on model parameters.

Findings

No SUSY signal observed

Constraints placed on AMSB parameter space

Excluded certain mass ranges for SUSY particles

Abstract

The DELPHI experiment at the LEP e+e- collider collected almost 700 pb^-1 at centre-of-mass energies above the Z0 mass pole and up to 208 GeV. Those data were used to search for SUSY in the Anomaly Mediated SUSY Breaking (AMSB) scenario with a flavour independent common sfermion mass parameter. The searches covered several possible signatures experimentally accessible at LEP, with either the neutralino, the sneutrino or the stau being the Lightest Supersymmetric Particle (LSP). They included: the search for nearly mass-degenerate chargino and neutralino, which is a typical feature of AMSB; the search for Standard-Model-like or invisibly decaying Higgs boson; the search for stable staus; the search for cascade decays of SUSY particles resulting in the LSP and a low multiplicity final state containing neutrinos. No evidence of a signal was found, and thus constraints were set in the space of the parameters of the model.