Speaker
Description
We carry out a systematic study of a broad class of UV completions of the Standard Model containing vector-like fermions and a complex scalar responsible for spontaneous PQ-symmetry breaking and the emergence of an axion-like particle (ALP). We classify the viable models and match them onto both SMEFT and ALP effective theories, deriving the corresponding low-energy descriptions for each case. This framework makes it possible to identify the characteristic operator patterns induced by each model and to uncover non-trivial correlations between the two EFT sectors. These correlations allow us to combine both sectors into a unified SMEFT-ALP EFT.We analyze this combined EFT using electroweak precision, Higgs, flavor, and axion constraints, and find that this framework provides a unified strategy to test different well-motivated ultraviolet scenarios.