Heavy Gravitino and Split SUSY in the Light of BICEP2

Understand

High-scale supersymmetry (SUSY) with a split spectrum has become increasingly interesting given the current experimental results.

• A SUSY scale above the weak scale could be naturally associated with a heavy unstable gravitino, whose decays populate the dark matter (DM) particles.
• In the mini-split scenario with gravitino at about the PeV scale and the lightest TeV scale neutralino being (a component of) DM, the requirement that the DM relic abundance resulting from gravitino decays does not overclose the Universe and satisfies the indirect detection constraints demand the reheating temperature to be below 10^9 - 10^{10} GeV.
• On the other hand, the BICEP2 result prefers a heavy inflaton with mass at around 10^{13} GeV and a reheating temperature at or above 10^9 GeV with some general assumptions.