학술논문

Probing the CP nature of the top–Higgs Yukawa coupling in t t ¯ H and tH events with H → b b ¯ decays using the ATLAS detector at the LHC
Document Type
article
Source
Subject
Nuclear and Plasma Physics
Particle and High Energy Physics
Physical Sciences
Mathematical Physics
Astronomical and Space Sciences
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Nuclear & Particles Physics
Mathematical sciences
Physical sciences
Language
Abstract
The CP properties of the coupling between the Higgs boson and the top quark are investigated using 139 fb−1 of proton–proton collision data recorded by the ATLAS experiment at the LHC at a centre-of-mass energy of s=13 TeV. The CP structure of the top quark–Higgs boson Yukawa coupling is probed in events with a Higgs boson decaying into a pair of b-quarks and produced in association with either a pair of top quarks, tt¯H, or a single top quark, tH. Events containing one or two electrons or muons are used for the measurement. Multivariate techniques are used to select regions enriched in tt¯H and tH events, where dedicated CP-sensitive observables are exploited. In an extension of the Standard Model (SM) with a CP-odd admixture in the top–Higgs Yukawa coupling, the mixing angle between CP-even and CP-odd couplings is measured to be α=11−73∘∘+52∘, compatible with the SM prediction corresponding to α=0.