Three-body gravitino decays in the MSSM

Understand

We present results from a new calculation of two- and three-body decays of the gravitino including all possible Feynman graphs.

• The work is done in the R-parity conserving Minimal Supersymmetric Standard Model, assuming that the gravitino is unstable.
• We calculate the full width for the three-body decay process Gravitino -> \chi_1 X Y, where \chi_1 is the lightest neutralino that plays the role of the lightest supersymmetric particle, and X, Y are standard model particles.
• For calculating the squared amplitudes we use the packages FeynArts and FormCalc, with appropriate extensions to accommodate the gravitino with spin 3/2.