Leinweber Seminar: Beyond Naive Naturalness: Light QCD Axions and Terrestrial Effects on Experimental Observables. - Abhishek Banerjee, University of Maryland

Beyond Naive Naturalness: Light QCD Axions and Terrestrial Effects on Experimental Observables.

Recent null results from LHC experiments and direct detection searches have motivated the exploration of light, weakly interacting new physics. In this context, the principle of naturalness remains pivotal, albeit in a nuanced and intricate manner. Notably, experimental sensitivity to light new physics is concentrated in parameter regions that might, at first glance, appear fine-tuned. This observation necessitates a framework that transcends naive naturalness expectations. In this work, I will examine these considerations in the context of the QCD axion, specifically outlining a strategy to realize a light QCD axion. Furthermore, I will discuss the effects of the Earth and the presence of matter on various experimental observables for light QCD axions, thereby requiring new experimental strategies and altering the existing bounds.