A composite axion from a supersymmetric product group

Abstract

Abstract A global U(1)PQ symmetry is protected from gravitational effects in the s-confining SU(N) k product group theory with A+4Q+NQ¯ $$ A + 4Q+N\overline{Q} $$ matter. If the SU(4) family symmetry is gauged and an appropriate tree-level superpotential is added, then the dynamically generated superpotential spontaneously breaks SU(4) × U(1)PQ → SU(3) c and produces a QCD axion. Small values of the CP -violating θ parameter are then possible without any fine-tuning, as long as the product group is suitably large. By introducing a second copy of the s-confining SU(N) product group also coupled to the gauged SU(4), we find that values as small as N = 7 are consistent with θ¯<10−10 $$ \overline{\theta}<1{0}^{-10} $$, even under the pessimistic assumption that the dominant contribution to the axion quality is at tree level.

Keywords

• Beyond Standard Model
• Confinement
• Spontaneous Symmetry Breaking
• Supersymmetry and Duality