A Journey with the Axion: From low energy effective field theory to dark matter detection

概要

The axion remains one of the most compelling candidates for new physics, offering solutions to both the strong CP problem and the nature of dark matter. This talk charts a journey with the axion, beginning with its fundamental theoretical description and later talk in new frontiers for its detection. The first part of this talk details axion low-energy phenomenology. We present a consistent derivation of the complete Wess-Zumino-Witten (WZW) interactions of axion by treating the 1-form axion derivative as a background field to ensure the physical consistency of the theory. We then expand this to construct a complete Lagrangian for axion interactions with both gauge bosons and the full spectrum of pseudoscalar and (axial-)vector mesons. This comprehensive framework, incorporating the chiral Lagrangian and the WZW term, provides a consistent basis for calculating physical observables, such as the decay widths of axions into hadronic final states.

The second part of talk shifts from theory to detection, focusing on the search for ultralight axion dark matter. We explore the untapped potential of higher-dimensional quantum systems, moving beyond standard qubits to a universal qutrit framework. We demonstrate how spin-1 NV-center qutrits can enhance the search for the axion-electron coupling by an order of magnitude, establishing higher-dimensional quantum sensing as a powerful new tool for probing fundamental physics.

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