In-situ Jet Calibration and Electro-Weak Induced Production of Wγ in Association With Two Jets at ATLAS

Abstract

Differential cross-section measurements of the electroweak production of W-gamma in association with two jets are made using proton-proton collision data with an integrated luminosity of 140fb−1 and a centre-of-mass energy of √s = 13 TeV, recorded by the ATLAS detector. Six different observables are used to present the differential cross-sections, where these observables are chosen due to their anticipated sensitivity to anomalous quartic gauge couplings and CP-violating interactions. The differential cross-section measurements are presented at particle-level after applying corrections to account for detector inefficiencies. These corrections are applied to differential signal yields which are obtained through a minimum log-likelihood fit of the data to simulations and data-driven background estimates. The measured differential cross-sections are compared to predictions from simulation, and are found to be compatible within statistical and systematic uncertainties. Correction factors to the jet energy scale calibration for large-radius jets are presented. These residual insitu corrections account for detector mismodelling in applying the simulation derived jet energy scale to data. The calibration is performed using Z+ jets events in both the electron and muon decay channels, and are found to be most relevant in the kinematic range of 200 GeV ≤ pT(jet) ≤ 500 GeV, where pT(jet) represents the jet transverse momentum. The total uncertainty on the insitu calibration factor is found to range from 0.5 − 1.5% depending on the decay channel and pT(jet) bin.

Date of Award	31 Dec 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Andrew Pilkington (Supervisor) & Darren Price (Supervisor)