Enhancing Higgs and top quark measurements with machine learning b-jet calibration in ATLAS - Brendon Bullard

Thursday 3 Oct 2024, 15:00 → 17:00 US/Eastern

Small Seminar Room

Abstract: One of the outstanding problems in modern physics is to understand the mechanism that gave rise to a matter-antimatter asymmetry in the universe today. One appealing solution is electroweak baryogenesis, which can be realized if new physics modifies the couplings of the Higgs boson relative to the Standard Model expectation. Measuring these properties requires the most precise reconstruction of decay products of the Higgs and top quarks, the most common of which are jets containing a B-hadron (b-jets). The rich substructure and unique decay patterns of b-jets have made machine learning-based identification algorithms ubiquitous in collider physics. This talk presents recent results from the ATLAS experiment extending this approach to calibration of the momentum and mass of b-jets. We demonstrate 30% improvement in the resolution of jet kinematics and 23% reduction on the width of the invariant mass peak from Higgs decays relative to the nominal jet calibration. The talk will conclude with an outlook on the next steps towards applying the algorithm for physics and how the HL-LHC could reveal physics pointing to electroweak baryogenesis.


zoom: https://cern.zoom.us/j/3194227134?pwd=NlJvTzBjeGl1ZXpBOHFoT1M5UmQxdz09