Séminaires du DPhP: Honing in on the Higgs boson’s top- and self-couplings
par
Chris Pollard(University of Oxford)
→
Europe/Paris
André Berthelot (CEA Paris-Saclay)
André Berthelot
CEA Paris-Saclay
Description
So far the measured properties of the Higgs boson are in line with the predictions of the Standard Model (SM) of particle physics. The Higgs field potential, as far as we can tell, underpins the spontaneous symmetry breaking of the weak sector as expected.
The shape of this potential is governed by two parameters in the SM: the Higgs boson mass and its self-coupling. The mass has been precisely measured with LHC data, but the Higgs boson’s self-interaction is yet to even be experimentally observed. The top quark, through its large Yukawa coupling to the Higgs boson, also plays a key role in Higgs phenomenology, with ramifications across physics. To take a well known example: the top-quark’s mass and the Higgs field’s self-interaction strength together determine the predicted stability of the electroweak vacuum.
We will survey the latest relevant results from the ATLAS experiment, focusing on measurements of the top-quark mass and searches for di-Higgs production — our strongest experimental probes of the top Yukawa coupling and the Higgs self-interaction strength — and their implications. We will then look to how future LHC analyses might improve upon the state-of-the art and discuss how current challenges and limitations are being overcome through modern machine learning techniques; precision ancillary measurements; and advances in high-frequency, real-time analysis.