Displaced vertices at the Tevatron from neutralino decays

por Diego Restrepo (IFIC)

martes 18 ene. 2005 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

Supersymmetric extensions of the standard model exhibiting bilinear $R$--parity violation can generate naturally the observed neutrino mass spectrum as well as mixings. One interesting feature of these scenarios is that the lightest supersymmetric particle (LSP) is unstable, with decay properties predicted in terms of neutrino parameters. A smoking gun of this model in colliders is the presence of displaced vertices due to LSP decays. In this work we focus on the simplest model of this type that comes from minimal supergravity with universal R--parity conserving soft breaking of supersymmetry (RmSUGRA). We evaluate the potentiality of the Fermilab Tevatron to probe the RmSUGRA parameters through the analysis of events possessing two displaced vertices stemming from LSP decays. We show that requiring two displaced vertices in the events leads to a reach in $m_{1/2}$ twice the one in the usual multilepton signals in a large fraction of the parameter space.