We provide an anthropic reason for the supersymmetry breaking scale being much higher than the electroweak scale, as indicated by the null result of collider experiments and the observed 125 GeV Higgs boson. We focus on a new inflation model as a typical low-scale inflation model that may be expected in the string landscape. In this model, R symmetry is broken at the minimum of the inflaton potential, and its breaking scale is related to the reheating temperature. Once we admit that the anthropic principle requires thermal leptogenesis, we obtain a lower bound for the gravitino mass, which is related to the R symmetry breaking scale. This scenario and resulting gravitino mass predict the consistent amplitude of density perturbations. We also find that string axions and saxions are consistently implemented in this scenario.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)