Grand unification and heavy axion

We argue that sufficiently complex grand unified theories involving extra strong intractions that confine at very short distances may lead to a heavy axion solution of the CP problem of QCD. This axion may have a mass within the accessible energy range, and its low-energy interactions emerge through mixing with axial Higgs boson(s). Another signature of this scenario is softly broken Peccei-Quinn symmetry in the electroweak Higgs sector. We present a toy GUT exhibiting these features. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 8, 590–593 (25 April 1997) Published in English in the original Russian journal. Edited by Steve Torstveit.