All Things EFT: Magic Zeroes in Effective Field Theory
Nathaniel Jay Craig
All Things EFT committee
29-06-2022 at 2:00 pm - 3:00 pm
Selection rules arising from accidental or broken symmetries may be sufficiently obscure that their agency is hidden, leading to the appearance of “magic zeroes” — quantities that are suppressed without apparent recourse to a symmetry explanation. Such magic zeroes and their corresponding hidden symmetries may shed new light on parametric hierarchies in effective field theories. In this talk, I’ll explore magic zeroes in the dipole moments of Standard Model leptons induced by heavy vector-like fermions, recently identified by Arkani-Hamed and Harigaya. In the absence of obvious symmetries, three novel explanations have been put forward: hidden conventional symmetries, on-shell selection rules, and total derivative phenomena. Each highlights subtleties in naturalness criteria for effective field theories and furnishes news tools in the hunt for magic zeroes.