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HEP Seminar: "New differential cross section measurements in the Higgs sector" with Sagar Addepalli

September 11, 2023
10:00 AM - 11:00 AM
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Pupin 705

"New differential cross section measurements in the Higgs sector"

The large dataset collected by the ATLAS experiment during Run 2 allows us to study the Higgs boson’s properties with much higher precision than ever before, opening up the hunt for inconsistencies between the Standard Model predictions and measurements. In this talk, I will present our latest measurements of the differential fiducial cross section of the vector boson fusion production of the Higgs boson in the H->WW->eνµν decay channel. This process is sensitive to the H-V coupling in its production as well as its decay. Sophisticated machine learning-based techniques are employed to separate the signal from the significant backgrounds. However, the naive use of such techniques induces biases that jeopardize the vital model-independence of the measurements. To reduce such biases, a multidimensional fit with an in-profile-likelihood unfolding technique is used to normalize the backgrounds from the same phase-space in which the signal is extracted. I will also discuss the interpretation of the results to put limits on new physics in the framework of Effective Field Theories. The novel methods employed for this measurement pave the way for future measurements of the cross sections of ever-so-small production rate processes. Such methods will be necessary for the model-independent exploration of the datasets from the forthcoming LHC runs. Lastly, I will discuss the projections for these measurements during the High Luminosity LHC era, when ATLAS will be able to take advantage of a new all-silicon Inner Tracker, the ITk.