The measurement of the ttH production was performed within the ATLAS experiment at the Large Hadron Collider. The Researcher set up the full physics analysis chain in C++ programming language and he coordinated the work within the analysis team at the Institute of Physics at JGU Mainz. The Researcher investigated various Higgs boson identification techniques and chose the one which improves the most the measurement sensitivity. The Researcher implemented a reconstruction technique for the top-antitop quark pair reconstruction in ttH events which further improved the separation between signal and background. Based on an optimized event selection to ensure the best trade off between ttH events and background in the boosted regime, the Researcher implemented a machine learning technique (Boosted Decision Trees) to increase the measurement sensitivity. The usage of deep neural networks was also tested for future improvement of the measurement.
The Researcher developed a new pileup mitigation method for jets (Iterative Constituent Subtraction) which can be used to improve the jet reconstruction at the LHC experiments and consequently improve the ttH measurement in the long term.
The Researcher gained expertise in multivariate analysis techniques (Boosted decision trees and Deep neural networks), classification optimization and the profile likelihood fit method. The researcher attended workshops on presentation skills, career planning, and on leadership skills. The Researcher co-supervised bachelor, master and PhD students, which improved his project management and leadership skills. The Researcher improved his management skills by thorough planning of the measurement in this project, which also includes management of computing resources and personpower.
List of conferences attended:
- 40th International Conference on High Energy Physics, virtual conference (Prague, Czech republic), Oral contribution: Pileup and Underlying Event Mitigation with Iterative Constituent Subtraction, 30 July 2020
- DPG conference, Aachen, Germany, Oral contribution: Pileup mitigation with Constituent Subtraction, 26 March, 2019
Scientific publications:
- ATLAS Collaboration: Measurement of the Higgs boson decaying to b-quarks produced in association with a top-quark pair in pp collisions at sqrt(s)=13 TeV with the ATLAS detector, ATLAS-CONF-2020-058
Open access at:
https://cds.cern.ch/record/2743685(odnośnik otworzy się w nowym oknie).
- P. Berta, L. Masetti, D. W. Miller, M. Spousta: Pileup and Underlying Event Mitigation with Iterative Constituent Subtraction, JHEP08 (2019) 175.
Open access at:
https://link.springer.com/article/10.1007%2FJHEP08%282019%29175(odnośnik otworzy się w nowym oknie) - ATLAS Collaboration: Optimisation of large-radius jet reconstruction for the ATLAS detector in 13 TeV proton-proton collisions, arXiv:2009.04986. This preprint is already submitted to high-impact journal EPJC.
Open access at:
https://arxiv.org/abs/2009.04986(odnośnik otworzy się w nowym oknie)- A. Basan, P. Berta, L. Masetti, E. Vryonidou, S. Westhoff: Measuring the top energy asymmetry at the LHC: QCD and SMEFT interpretations, JHEP03 (2020) 184.
Open access at:
https://link.springer.com/article/10.1007%2FJHEP03%282020%29184(odnośnik otworzy się w nowym oknie)List of outreach activities:
- Poster presentation at a public event called “Institutstag”, Institute of Physics, JGU Mainz, Germany, 27.6.2019.
- Realization of Masterclasses for high school students, Frankfurt International School, Frankfurt am Main, Germany, 10.4.2019.
