Abstract:

The report presents the results, obtained in the thesis titled “Study of vector boson pair production decaying into charged leptons and hadrons with the ATLAS experiment” for the degree of a candidate of physical and mathematical sciences, specialty 01.04.23 – high-energy physics.

One of the topical areas of high-energy physics research is the search for signs of New Physics, extensions of the Standard Model (SM). Some of models predict non-resonant manifestation of New Physics through a change in the cross-section of the vector boson scattering process VV → VV (V = W, Z) predicted in the electroweak sector of the SM. This report presents the results of the first measurement of the cross-section of this process, performed on the data recorded with the ATLAS detector in 2015 and 2016.

In addition, the search for diboson resonances was performed within the Two-Higgs-Doublet Model as the simplest non-minimal model of electroweak symmetry breaking, the heavy vector triplet model which has phenomenological properties of many SM gauge sector extensions and the extended Randall – Sandrum model which allows explaining gravitational interaction weakness. The data were recorded with the ATLAS detector from 2015 to 2018 at the Large Hadron Collider.

Also, the report presents the result of the ATLAS muon trigger upgrade performed in 2014-2015 to provide trigger suppression of false muon events in the forward kinematic regions of the ATLAS detector.