Effective Field Theory Approach to New Physics Searches

by Prof. Janusz Rosiek (Warsaw U.)

Wednesday 17 Apr 2024, 16:00 → 18:00 Asia/Seoul

Room 1423 (KIAS)

Title: Effective Field Theory Approach to New Physics Searches

Speaker: Prof. Janusz Rosiek (Warsaw U.)

Abstract: I will describe the model-independent approach to searching
for the New Physics traces in the precise measurements of the SM
particle interactions properties using the Effective Field Theory formalism.

1. I will justify and formulate the Effective Field Theory
generalization of the SM (and in general also other low-energy models
like 2HDM or MSSM). In principle, all UV completions of the SM can be
described via their EFT limit as long as one considers interaction
energies well below the mass scale of new particles.

2. I will describe the construction of the SM-EFT Lagrangian in
symmetric and broken (after SSB mechanism) phases - derivation of the
minimal operator basis and identifying physical fields and their
interactions.

3. I will describe developing the setup for EFT amplitude calculations,
both at tree and loop level: proper quantization of the theory (gauge
fixing choice), input parameter choice and reparametrization issues,
renormalization scheme choices. I will illustrate it with examples of
non-trivial loop calculations (l->l' gamma and H->2 gamma/Z gamma).

4. I will discuss automating the calculations within the EFT using
public software libraries, with the example of SmeftFR package. I
present how to apply SmeftFR to provide input for either analytical
amplitude calculations (e.g. with FeynCalc or similar) or Monte Carlo
event generators (e.g. MadGraph 5 or other UFO-format compatible programs).

This talk is based on long series of papers published 2010-2024.