Bypassing the Axion Paradigm through Fractional Field Theory

Abstract

A long-standing challenge of the Standard Model (SM) is to convincingly explain the physical mechanism behind the  axial anomaly of Quantum Chromodynamics (QCD). While instantons are routinely invoked as solution to this anomaly, they create new puzzles – the strong CP problem and the postulated existence of axions. Here we suggest that fractional field theory offers an alternative resolution of the axial anomaly, shedding new light on the strong CP problem and bypassing the axion hypothesis.