Peccei-Quinn invariant singlet extended SUSY with anomalous U(1) gauge symmetry

Abstract

Recent discovery of the SM-like Higgs boson with $m_h\simeq 125$ GeV motivates an extension of the minimal supersymmetric standard model (MSSM), which involves a singlet Higgs superfield with a sizable Yukawa coupling to the doublet Higgs superfields. We examine such singlet-extended SUSY models with a Peccei-Quinn (PQ) symmetry that originates from an anomalous $U(1)_A$ gauge symmetry. We focus on the specific scheme that the PQ symmetry is spontaneously broken at an intermediate scale $v_{\rm PQ}\sim \sqrt{m_{\rm SUSY}M_{\rm Pl}}$ by an interplay between Planck scale suppressed operators and tachyonic soft scalar mass $m_{\rm SUSY}\sim \sqrt{D_A}$ induced dominantly by the $U(1)_A$ $D$-term, $D_A$. This scheme also results in spontaneous SUSY breaking in the PQ sector, generating the gaugino masses $M_{1/2}\sim \sqrt{D_A}$ when it is transmitted to the MSSM sector by the conventional gauge mediation mechanism. As a result, the MSSM soft parameters in this scheme are induced mostly by the $U(1)_A$ $D$-term and the gauge mediated SUSY breaking from the PQ sector, so that the sparticle masses can be near the present experimental bounds without causing the SUSY flavor problem. The scheme is severely constrained by the condition that a phenomenologically viable form of the low energy operators of the singlet and doublet Higgs superfields is generated by the PQ breaking sector in a way similar to the Kim-Nilles solution of the $μ$ problem, and the resulting Higgs mass parameters allow the electroweak symmetry breaking with small $\tanβ$. We find two minimal models with two singlet Higgs superfields, satisfying this condition with a relatively simple form of the PQ breaking sector, and briefly discuss some phenomenological aspects of the model.