#### The Phenomenology of Decoupled New Physics in Effective Field Theory

- Event time: 2:00pm
- Event date: 1st March 2017
- Speaker: Jeremie Quevillon (Kings College London)
- Location: Higgs Centre Seminar Room, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB

### Event details

If the Physics Beyond the Standard Model (BSM) is decoupled at higher energies, the Standard Model as an effective field theory (SM EFT) is a pertinent framework for phenomenology. The BSM effects on observables are parametrized by the Wilson coefficients of dimension-6 operators, and bounds on their values can be placed from experimental measurements. Integrating out heavy particles at one-loop to obtain expressions for the Wilson coefficients is now also simplified by the use of our universal one-loop effective action. We show how the one-loop effective action obtained from the path integral Covariant Derivative Expansion method can be written in a universal closed form. This result has general applicability beyond the SM EFT and can be used for integrating out any UV theory to obtain a low-energy EFT. We illustrate the relationship of our results to the Standard Model EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.

We will also cover the alternative scenario where the New Physics is also directly produced at the LHC by analyzing a selection of interesting direct searches of Supersymmetric heavy Higgs bosons.

The Particle Physics Theory seminar is a weekly series of talks reflecting the diverse interests of the group. Topics include analytic and numerical calculations based on the Standard Model of elementary particle physics, theories exploring new physics, as well as more formal developments in gauge theories and gravity..