Speaker: Xiaochuan Lu
Title: Constraining BSM custodial violations beyond the oblique framework
Zoom: https://zoom.us/j/186024391
Host: Markus Luty
Abstract: BSM custodial violations are believed to be strongly constrained by electroweak precision measurements. In particular, they result in a nonzero Peskin-Takeuchi T parameter, which is experimentally bounded at the per-mille level. However, the T parameter constraint only applies to oblique BSM physics. When the BSM effects are not oblique, T parameter is no longer an observable, and it fails to serve as an indicator of BSM custodial violations. We take a first step at addressing this problem by working with SMEFT at the dim-6 and tree level. We identify new observables that can serve as unambiguous indicators of BSM custodial violations.
