My primary research interest is the physics of elementary particles at the energy frontier. My research focuses on the ATLAS Experiment, a general-purpose detector at CERN’s Large Hadron Collider (LHC) in Geneva, Switzerland, which I joined as an undergraduate in 2015 and continue to work on as a PhD student at the University of Toronto.

Using proton-proton collision data collected by ATLAS during Run-2 of the LHC, my data analysis activities have focused on Higgs boson physics and searches for physics beyond the Standard Model in the Higgs sector. Since joining ATLAS, I have worked with the H → ZZ group and have contributed to several analyses studying Higgs physics in the four-lepton final state. The majority of this work has centred on a search for a heavy Higgs boson. For this analysis I developed and maintain software to parametrize the signal and background distributions from Monte Carlo simulations. I also contributed to the group’s Ntuple production, where raw collision events from data and simulation are reconstructed, calibrated, and the events of interest are identified and processed into a format that can be used for the analysis.

I relocated to CERN in Oct 2017 until Dec 2018 to work on operations of the ATLAS liquid argon (LAr) calorimeters. During this time, I developed a new software application with a graphical user interface to take special calibrations of individual segments of the LAr calorimeters, which is being used for the commissioning of the upgraded LAr readout system during the 2019-2020 shutdown of the LHC. In addition to contributing to other areas of the LAr online software infrastructure, I also acted as a LAr on-call expert and LAr run coordinator, taking week-long shifts throughout the year while the LHC was in operation. The primary responsibilities of the on-call experts and run coordinators are to ensure good detector performance during data-taking, coordinate calibration runs and interventions on the system with ATLAS Run Coordination, and to act as a first point of contact in case of problems with the LAr calorimeters.

Since Oct 2017, I have also been the LAr contact to the ATLAS luminosity group. As the LAr contact, my main task is to process the signal from the electromagnetic end-cap (EMEC) and forward calorimeters (FCal) and calibrate it to give a measurement of the luminosity of the hadron collisions at the ATLAS interaction point. The LAr luminosity is then used to study the long-term stability of the primary ATLAS luminosity algorithm. One major contribution I made in this area was the development of a correction to the FCal luminosity to account for a non-linearity in the detector’s response, which was an important factor in reducing the luminosity stability uncertainty in the 2017 and 2018 pp datasets from about 1.3% to 0.8%.

My research activities as an undergraduate prior to 2015 focused on developing x-ray imaging techniques in medical radiography. Here I studied two imaging methodologies: dual-energy radiography, a method used to suppress beam-hardening artefacts and remove contrast from objects not of diagnostic interest, and x-ray scatter imaging, a novel technique to increase soft tissue contrast. For these studies, I first developed a computer application to simulate the acquisition of an x-ray scatter image using multiple pencil beams. I then used the simulated data to test the efficacy of a Maximum-Likelihood Expectation Maximization (MLEM) algorithm to disentangle the overlapping scatter patterns from each individual beam. With this insight gained, the MLEM algorithm was later modified to reduce a ghosting effect from scattered photons appearing in other columns of the image. Alongside this project, I also designed and oversaw the construction of an aluminum optics bench to assess the utility of an x-ray imaging detector donated by the Ottawa Hospital for x-ray scatter imaging and dual-energy radiography. This optics bench was necessary to stabilize the x-ray components and allowed for more precise and reproducible measurements.