Key points are not available for this paper at this time.
A SU (N) ₋ (N) ₑ gauge theory for a scalar multiplet Y transforming in the bifundamental representation (N, N) preserves, for N>4, an accidental U (1) symmetry first broken at operator dimension N. A vacuum expectation value for Y can break the symmetry to Hₒ=SU (N) ₋+ₑ or to H₇=0ex{0ex}SU (N-1) ₋ (N-1) ₑ (1) ₋+ₑ. In the first case the accidental U (1) gets also broken, yielding a pseudo-Nambu-Goldstone boson with mass suppression controlled by N. In the second case a global U (1) remains unbroken. The strong CP problem is solved by coupling Y to new fermions carrying color. The first case allows for a Peccei-Quinn solution with U (1) ₐ protected by the gauge symmetry up to order N. In the second case U (1) can get broken by condensates of the new strong dynamics, resulting in a composite axion. By coupling Y to fermions carrying only weak isospin, models for axionlike particles can be constructed.
Luzio et al. (Thu,) studied this question.