Particle Theory Seminar | Nathaniel Craig (UCSB) – Effective Field Theory and the Geometry of Electroweak Symmetry Breaking

Seminar Organizer

Event Details


There are two canonical approaches to treating the Standard Model as an effective field theory: the Standard Model EFT (SMEFT), respecting the full electroweak gauge symmetry, and the Higgs EFT (HEFT), respecting only electromagnetism. Of these, SMEFT has become the predominant framework for interpreting LHC Higgs data and exploring the systematics of effective field theory. This raises a number of questions: Is HEFT relevant in light of current data? What types of UV physics (if any) require HEFT, rather than SMEFT? Is SMEFT enough?

In this talk, I’ll develop a geometric picture of SMEFT and HEFT that provides sharp criteria for determining the appropriate EFT for the Higgs sector, illuminating the physical scenarios that require HEFT and arguing that SMEFT is not enough. I’ll draw further connections between this geometric picture, scattering amplitudes, and the scale of unitarity violation in the two EFTs, ultimately framing a compelling open question for the LHC and future colliders: is electroweak symmetry linearly realized by the known particles?

Troy Cortez is inviting you to a scheduled Zoom meeting.

Join Zoom Meeting

Meeting ID: 170 483 588

One tap mobile
+16699006833,,170483588# US (San Jose)
+13462487799,,170483588# US (Houston)

Dial by your location
+1 669 900 6833 US (San Jose)
+1 346 248 7799 US (Houston)
+1 253 215 8782 US
+1 301 715 8592 US
+1 312 626 6799 US (Chicago)
+1 646 558 8656 US (New York)
Meeting ID: 170 483 588
Find your local number:

Join by SIP

Join by H.323 (US West) (US East) (China) (India Mumbai) (India Hyderabad) (EMEA) (Australia) (Hong Kong) (Brazil) (Canada) (Japan)
Meeting ID: 170 483 588