High Energy Phenomenology Seminar: Kevin Zhang (University of California, Santa Barbara) "Magic Zeroes and Hidden Symmetries"
Speaker: |
(sign-up)
Kevin Zhang |
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Date: | 9/23/2022 |
Time: | 11 a.m. |
Location: | Room 464 |
Event Contact: | Brandy Koebbe BKOEBBE@ILLINOIS.EDU |
Sponsor: | Department of Physics |
Event Type: | Seminar/Symposium |
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. Magic zeroes and their corresponding hidden symmetries may shed new light on parametric hierarchies in the Standard Model and beyond. We identify the hidden symmetry responsible for a recently-discovered magic zero, the vanishing of the putative leading contribution to the anomalous dipole moments of the muon upon integrating out weak doublet and singlet vector-like fermions. Some of the tools involved – spurion analysis leveraging discrete symmetries of the free theory, field redefinitions, spectator fields, and non-supersymmetric non-renormalization theorems – may prove useful in the hunt for new magic zeroes and their hidden symmetries. |