Master Thesis Defense: Shengtang Yi

Title: Study of anomalous ttbar production in the di-lepton final state at FCC-ee


The top quark, as the most massive of all observed elementary particles, has the exclusive advantage of being the optimal candidate to reveal the mystery of physics beyond the Standard Model of particle physics (BSM). Anomalous contributions to ttbar production can be investigated in Standard Model Effective Field Theory ( SMEFT) framework.

The potential new contributions are expected to affect the production cross-section and angular distributions of the top decay products. The Future Circular Collider (FCC) process e+e- to ttbar will be simulated using the FCC IDEA detector setup and investigated with the FCC analysis software to gauge the potential experimental sensitivity to anomalous top contributions. The project will focus on the final state with two b-jets and two charged leptons. The analysis uses single and multidimensional angular distributions to determine the sensitivity of single and multi-parameter fits of the couplings for the feasibility study of FCC-ee.

The presentation will give an overview of anomalous ttbar production at FCC-ee with focus on analysis steps, event selection, kinematic reconstruction and coupling determination.