EFT below the electroweak scale and constraints on New Physics

Peter Stoffer (UC San Diego)

Abstract:

Under the assumption that physics beyond the standard model consists of heavy particles well above the electroweak scale, its effects at lower energies can be described by an effective field theory. Below the electroweak scale, this resembles the well-known Fermi theory of weak interactions. I will present the complete operator basis for this low-energy effective field theory (LEFT) up to dimension six as well as the calcultion of the full one-loop RGEs.

At low energies, strong constraints on some LEFT Wilson coefficients come e.g. from lepton-flavour-violating observables or electric dipole moments (EDMs). In order to exploit the full power of neutron EDM measurements, the uncertainties of hadronic matrix elements should be reduced, ideally with lattice calculation. In the second part of the talk, I will explain the ingredients of a matching calculation between the LEFT framework and a scheme that can be implemented on the lattice.