Joshua Clercx

Notkestraße 85 (Building 1c)
22607 Hamburg
Room: O2.302



Combination of Higgs boson measurements at ATLAS using simplified template cross sections
Supervisors: Prof. Kerstin Tackmann (DESY), Prof. Peter Schleper (DESY)

Joshua studied physics and astronomy at Ghent University in Ghent, Belgium. His interests are broad and he took courses during his bachelor’s and master’s in subjects such as biology, history, and climatology. For his bachelor’s thesis he built a weather-station and performed some simple data analysis with the measurements. When he finished his bachelor’s degree, he decided that experimental particle physics was what he really wanted to focus on though. After spending a summer at CERN as an intern looking at WZ boson production at CMS, he performed his master’s thesis where he analyzed top quark pair production in association with a Z boson in the dilepton channel, also at CMS.
He then wanted to continue his academic career in a challenging and stimulating environment, which is how he ended up at DESY in Hamburg where he is currently performing a doctoral project in Higgs physics. Specifically, he is helping to make precise measurements in the Higgs sector by combining measurements of different production processes and decay mechanisms. The Simplified Template Cross Section (STXS) measurements framework, which he uses for this purpose, defines cross sections of mutually exclusive regions of phase space, which are defined per production process. Precise measurements are important because they could show deviations from the theoretical predictions, which would indicate the existence of physics beyond the standard model. The data he uses comes from the LHC Run2 from 2015 to 2018, and will be combined first within ATLAS, and later together with CMS. Besides the topics related to his project, he is also interested in machine learning techniques to aid analyses, effective field theories, and subjects related to physics beyond the standard model, dark matter, exotic particles, etc.