Heavy Gravitino and Split SUSY in the Light of BICEP2
  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. The mild tension could be alleviated if SUSY
scale is even higher with the gravitino mass above the PeV scale. Intriguingly,
in no-scale supergravity, gravitinos could be very heavy at about 10^{13} GeV,
the inflaton mass scale, while gauginos could still be light at the TeV scale.
