Speaker
Maria Ramos
Description
We demonstrate that the true QCD axion that solves the strong CP problem can be found in all generality outside the customary standard QCD band, with QCD being the sole source of Peccei-Quinn breaking. The essential reason is that the basis of axion-gluon interactions does not need to coincide with the mass basis, namely the QCD axion can mix with other scalar fields in Nature. We determine in all generality the condition for an arbitrary N-scalar potential to be PQ invariant, together with a precise sum rule for the multiple QCD axion and other exact results.
