Reach and complementarity of $$\mu \rightarrow e$$ μ → e searches

Abstract

Abstract In Effective Field Theory, we describe $$\mu \leftrightarrow e$$ μ ↔ e flavour changing transitions using an operator basis motivated by experimental observables. This implies that $$\mu \rightarrow e_L \gamma $$ μ → e L γ , $$\mu \rightarrow e_L \bar{e} e$$ μ → e L e ¯ e and $$\mu \rightarrow e_L$$ μ → e L conversion on nuclei probe a six-dimensional subspace, where we derive constraints on the New Physics scale from past and future experiments, illustrating the complementarity of the processes in an intuitive way.