Natural split mechanism for sfermions: N=2 supersymmetry in phenomenology

Abstract

We suggest a natural split mechanism for sfermions based on N=2 supersymmetry (SUSY). N=2 SUSY protects a sfermion in an N=2 multiplet from gaining weight by SUSY breaking. Therefore, if partly N=2 SUSY is effectively obtained, a split spectrum can be realized naturally. As an example of the natural split mechanism, we build a gauge-mediated SUSY breaking-like model assuming N=2 SUSY is partly broken in an underlying theory. The model explains the Higgs boson mass and muon anomalous magnetic dipole moment within 1 σ level with a splitting sfermion spectrum. The model has seven light sparticles described by three free parameters and predicts a new chiral multiplet, sb: the N=2 partner of the N=1 U(1)Y vector multiplet. The bini, the fermion component of the sb, weighs MeVs. We mention the experimental and cosmological aspects of the model.