Factoring the Strong CP Problem

We present a new mechanism to solve the strong CP problemusing $N\geq2$ axions, each dynamically relaxingpart of the $\barθ$ parameter. At high energies $M\ggΛ_{QCD}$ the $SU(3)_{c}$ group becomes the diagonal subgroupof an $SU(3)^{N}$ gauge group, and the non-perturbativeeffects in each individual $SU(3)$ factor generate a potential for the corresponding axion. The vacuum is naturally aligned to ensure $\barθ=0$ at low energies, and the masses of these axionscan be much larger than for the standard QCD axion. This mechanism avoids the introduction of a discrete $Z_2$ symmetry and associated 'mirror' copies of the SM fermions, and also avoids the introduction and stabilization of new light colored states to modify the running of the QCD gauge coupling found in other heavy axionmodels. This strengthens the motivation for axion-like particles solving the strong CP problemat pointsbeyond the standard QCD axioncurve in the $(m_a, f_a)$ plane.