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Chinellato, J.

Publications and source records attributed to Chinellato, J..

99 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Measurements of $t\overline tH$ Production and the CP Structure of the Yukawa Interaction between the Higgs Boson and Top Quark in the Diphoton Decay Channel

The first observation of the t t ¯ H process in a single Higgs boson decay channel with the full reconstruction of the final state ( H → γ γ ) is presented, with a significance of 6.6 standard deviations ( σ ). The C P structure of Higgs boson couplings to fermions is measured, resulting in an exclusion of the pure C P -odd structure of the top Yukawa coupling at 3.2 σ . The measurements are based on a sample of proton-proton collisions at a center-of-mass energy s = 13 TeV collected by the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb – 1 . The cross section times branching fraction of the t t ¯ H process is measured to be σ t t ¯ H B γ γ = 1.56 – 0.32 + 0.34 fb , which is compatible with the standard model prediction of 1.13 – 0.11 + 0.08 fb . The fractional contribution of the C P -odd component is measured to be f C P H t t = 0.00 ± 0.33 .

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Identification of heavy, energetic, hadronically decaying particles using machine-learning techniques

Machine-learning (ML) techniques are explored to identify and classify hadronic decays of highly Lorentz-boosted W/Z/Higgs bosons and top quarks. Techniques without ML have also been evaluated and are included for comparison. The identification performances of a variety of algorithms are characterized in simulated events and directly compared with data. The algorithms are validated using proton-proton collision data at $\sqrt{s}$ = 13TeV, corresponding to an integrated luminosity of 35.9 fb -1 . Systematic uncertainties are assessed by comparing the results obtained using simulation and collision data. The new techniques studied in this paper provide significant performance improvements over non-ML techniques, reducing the background rate by up to an order of magnitude at the same signal efficiency.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

A measurement of the Higgs boson mass in the diphoton decay channel

A measurement of the mass of the Higgs boson in the diphoton decay channel is presented. This analysis is based on 35.9 fb$^{-1}$ of proton-proton collision data collected during the 2016 LHC running period, with the CMS detector at a center-of-mass energy of 13 TeV. A refined detector calibration and new analysis techniques have been used to improve the precision of this measurement. The Higgs boson mass is measured to be $m_\mathrm{H} =$ 125.78$\pm$0.26 GeV. This is combined with a measurement of $m_\mathrm{H}$ already performed in the H$\to$ZZ$\to$4$\ell$ decay channel using the same data set, giving $m_\mathrm{H} =$ 125.46$\pm$0.16 GeV. This result, when further combined with an earlier measurement of $m_\mathrm{H}$ using data collected in 2011 and 2012 with the CMS detector, gives a value for the Higgs boson mass of $m_\mathrm{H} =$ 125.38$\pm$0.14 GeV. This is currently the most precise measurement of the mass of the Higgs boson.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗