Particle Physics Seminars at BNL

An experimental overview of effective field theory exploration at the LHC

by Saptaparna Bhattacharya (Northwestern University)


The effective field theory (EFT) approach posits that in a scenario where new particles cannot
be observed directly at low energy, the source of new physics are heavy fields beyond our current
reach. The Standard Model (SM) Lagrangian contains fields of dimension-4 and the EFT frame-
work extends the SM Lagrangian in an expansion in inverse powers of the scale of new physics.
Within this framework, the potential impact of higher dimensional operators can be explored.
The most common example of an EFT appears in the Fermi theory of weak interactions where
the appearance of the four Fermi vertex features an operator of dimension-6. In this talk, I will
provide an overview of EFT explorations at the LHC. With the collection of more than 150 fb^-1
of data at the LHC, rare processes predicted in the Standard Model have become accessible.
These rare processes can be used as probes of new physics using the EFT framework. The large
dataset also enables precision measurements of certain processes allowing the ability to study
deviations from SM expectations and characterizing the nature of potential excesses within the
EFT formalism. I will focus on the exploration of dimension-6 and dimension-8 operators at the
LHC in final states arising out of the decay of multiple gauge bosons. I will provide a snapshot
of LHC Run II analyses as we embark on Run III.

Organized by

Tobias Neumann