Messenger inflation in gauge mediation and super-WIMP dark matter

We discuss phenomenological viability of a novel inflationary model in the minimal gauge mediated supersymmetry breaking scenario. In this model, cosmic inflation is realized in the flat direction along the messenger supermultiplets and a natural dark matter candidate is the gravitino from the out-of-equilibrium decay of the binolike neutralino at late times, which is called the super-WIMP scenario. The produced gravitino is warmish and can have a large free-streaming length; thus the cusp anomaly in the small scale structure formation may be mitigated. We show that the requirement of the Standard Model Higgs boson mass to be mh0 = 125.1 GeV gives a relation between the spectrum of the cosmic microwave background and the messenger mass M. We find, for the e-folding number Ne = 60, the Planck 2018 constraints (TT, TE, EE + lowE + lensing + BK15 + BAO, 68% confidence level) give M 3.64 x 107 GeV. The gravitino dark matter mass is m3/2 < 5.8 GeV and the supersymmetry breaking scale ? is found to be in the range (1.28-1.33) x 106 GeV. Future cosmic microwave background observation is expected to give tighter constraints on these parameters.

Automated summary

A novel inflationary model in the context of gauge mediated supersymmetry breaking is discussed, with implications for dark matter and cosmic microwave background radiation. Relations between the gravitino dark matter mass and supersymmetry breaking scale are found, and future observations are expected to provide tighter constraints on these parameters.