Measurements of H(->WW)+jets with the ATLAS detector

Using data produced by the Large Hadron Collider and collected by the ATLAS detector, differential cross sections of H(->WW)+jets will be measured and interpreted in the context of an effective field theory. The measurements will be optimized for the separation of various production channels: gluon fusion, vector-boson fusion, and VH production. The impact of the background subtraction on the interpretation will be studied, and the results will be combined with other Higgs boson measurements. Broader interpretations of flavour violation and specific new resonances or models will be investigated.

The programme will begin with a detailed study of the identification of b-quarks produced in the top-quark decay, as this provides the dominant background to H(->WW)+jets. The study will focus on improving existing algorithms to increase the efficiency for b-quark identification so as to maximize the top-quark rejection. Steps will then be taken to calibrate the Monte Carlo modelling of this efficiency using top-quark data.

The improved b-quark identification will subsequently be incorporated into the existing H(->WW) measurement framework, and a method will be devised to determine the residual top-quark background using the calibrated b-tagging algorithm. The dependence of the event selection on effective operators affecting both H(->WW)+jets and top-quark production will be investigated, and several selections will be chosen to maximize global sensitivity to the operators. Measurements of cross sections in these regions will be performed both inclusively and differentially, and combined with other measurements from ATLAS to globally constrain operators at a given order in the effective field theory. Separate studies will be performed to investigate potential flavour-dependent processes and specific resonances that significantly affect the operators relevant to H(->WW)+jets production.