Title: Top-ics in Standard Model Effective Field Theory 
Speaker: Dr. Ken Mimasu(CP3, UCL) 
Time: 3:00pm, November 9th (Friday), 2018 
Place: R319, Theoretical Physics Division 

Abstract:The Standard Model Effective Field Theory (SMEFT) provides a consistent formalism to parametrise the effects of heavy new physics in new operators composed of Standard Model particles. One of the key programmes of the LHC is to interpret measurements in this framework to deepen our understanding of SM interactions and extend the energy reach of the collider with respect to new physics. To this end, precise predictions for all observables of interest in the SMEFT are required, both at fixed order and for Monte Carlo event generators interfaced with parton showers. In the first part, the speaker will discuss recent developments towards a first complete model implementation of SMEFT next-to-leading order in QCD. To showcase the model, he will present a phenomenological study of single-top production in association with a Higgs or Z boson at the LHC, framed in the context of probing the interactions of the Electroweak symmetry breaking sector. In the second part, he will present a sensitivity study for operators involving four heavy quarks in ttbb production at the LHC at present and in the future. This study exploits novel machine learning techniques to not only discriminate between SM and EFT effects but also distinguish between operators that mediate different top helicities. These methods have a broad applicability and are found to effectively pinpoint the origin of possible observed deviations in the model parameter space.