Recent theoretical papers have proposed new phenomenological scenarios
where the gravitino is light and the supersymmetric partner of the
goldstino, the sgoldstino, can be of low mass so as to be detectable at
LEP..
An novelty of this framework is that the sgoldstino being a particle,
its decay chains do not involve other supersymmetric particles, like the
LSP (lightest supersymmetric particle),
which could escape detection and lead to final states with missing energy.
A search for sgoldstino has been performed , for the first time, in
DELPHI.
At LEP2 sgoldstinos are mainly produced accompanied by a photon.
This process is followed by S decay into two gluons or two
photons, leading to final states with three photons or two jets and one
photon.Both these topologies were studied in DELPHI
for 189-202 GeV centre-of-mass energies.
The poster will introduce the Sgoldstino phenomenology, discussing the
productions mechanisms, the decay chains
and the particle width, depending on the parameters of the model considered.
The attention will be focused on the sgoldstino search performed in
DELPHI and on the results obtained.