PKU-SJTU Collider Physics Forum for Junior Scholars (京沪云坛 No.7): The top quark and new physics at the LHC

by Dr Yang Qin (University of Manchester)

Friday 12 Aug 2022, 19:00 → 20:30 Asia/Shanghai

Online (Cloud)

STJU indico cross-reference: https://indico-tdli.sjtu.edu.cn/event/1233/

Zoom Meeting: 624 1811 8759 (Passcode: 341548)

Abstract: 

As the heaviest elementary particle in the SM, the top quark has been studied in great detailed at the LHC. Given its extraordinary properties, many BSM theories predict new physics in the top quark sector. Searches have been performed at the LHC using events with top quarks in the final state, targeting different types of new physics. 

This seminar highlights a few recent results probing resonant and non-resonant new physics. Searches for new heavy vector, scalar and pseudo-scalar bosons in events with four top quarks (tttt) are first presented. This is followed by a discussion on the potential of using tttt events to probe non-resonant new physics, under the Effective Field Theories (EFT) framework and in top-Higgs Yukawa coupling. In addition, a dedicated measurement of the CP properties of the top-Higgs Yukawa coupling using ttH events is presented. 

 

Biography: 

Dr Yang Qin (秦暘) is a post-doctoral researcher at the University of Manchester. He is currently leading the Heavy Quarks and Top (HQT) working group of the ATLAS Collaboration, with ~20 on-going analyses and ~80 members. Dr Yang Qin obtained his PhD degree in 2016 from the University of Manchester under the supervision of Professor Christian Schwanenberger (now a leading scientist at DESY and professor at the University of Hamburg, Germany). He has been dedicated to measurements and new physics searches in the top quark and Higgs boson sectors as well as their inter-sector. His PhD work led to the paradigm measurement of ttH production with H->bb decay at 8 TeV, and the world’s first measurement of the ttbar production cross section at 13 TeV. As a post-doctoral researcher, he has led several new physics searches, including heavy charged Higgs boson, heavy scalar/pseudo-scalar/vector bosons in top-quark final states. His recent publication established the first evidence of the simultaneous production of four top quarks at the LHC.