Measurements of Higgs boson properties in the diphoton decay channel with 36 fb−1 of 𝑝𝑝 collision data at 𝑠√=13 TeV with the ATLAS detector

H. WAHLBERG Y ATLAS COLLABORATION

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Lugar: New York; Año: 2018

1550-7998

Properties of the √ Higgs boson are measured in the two-photon final state using 36.1 fb −1 of proton?proton collisiondata recorded at s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. Cross-section measurementsfor the production of a Higgs boson through gluon?gluon fusion, vector-boson fusion, and in association with avector boson or a top-quark pair are reported. The signal strength, defined as the ratio of the observed to the expectedsignal yield, is measured for each of these production processes as well as inclusively. √ The global signal strengthmeasurement of 0.99 ± 0.14 improves on the precision of the ATLAS measurement at s = 7 and 8 TeV by a factorof two. Measurements of gluon?gluon fusion and vector-boson fusion productions yield signal strengths compatiblewith the Standard Model prediction. Measurements of simplified template cross sections, designed to quantify thedifferent Higgs boson production processes in specific regions of phase space, are reported. The cross section for theproduction of the Higgs boson decaying to two isolated photons in a fiducial region closely matching the experimentalselection of the photons is measured to be 55±10 fb, which is in good agreement with the Standard Model predictionof 64 ± 2 fb. Furthermore, cross sections in fiducial regions enriched in Higgs boson production in vector-bosonfusion or in association with large missing transverse momentum, leptons or top-quark pairs are reported. Differentialand double-differential measurements are performed for several variables related to the diphoton kinematics as wellas the kinematics and multiplicity of the jets produced in association with a Higgs boson. These differential crosssections are sensitive to higher order QCD corrections and properties of the Higgs boson, such as its spin and CPquantum numbers. No significant deviations from a wide array of Standard Model predictions are observed. Finally,the strength and tensor structure of the Higgs boson interactions are investigated using an effective Lagrangian, whichintroduces additional CP-even and CP-odd interactions. No significant new physics contributions are observed.