Current research projects
Top-quark physics with the ATLAS detector at CERN
Together with postdoctoral researchers, PhD students and master's students I'm pursuing a comprehensive research program on top-quark physics. We use data collected with the ATLAS detector which records proton-proton collision data of the Large Hadron Collider (LHC) at CERN. Currently, we are analysing data which were taken in the years 2015 to 2018 at a center-of-mass energy of 13 TeV. The following analyss efforts are ongoing.
- Measurement of the total cross-section of single top-quark production in the t-channel at a center-of-mass-energy of 13 TeV. Determination of the CKM-matrix element Vtb.
- Measurement of differential cross-sections of single top-quark production in the t-channel. Interpretation of the measurements in the context of the effective field theory approach and comparison of the measured distributions with predictions by different Monte Carlo event generator setups. More information on our research on single top quarks: web page in German.
- Measurement of the top-quark mass in a data set enriched in single top-quark t-channel events. Usage of Monte Carlo events generators featuring off-shell top quarks.
- Search for flavour-changing neutral-current (FCNC) couplings between the top quark and the Higgs boson. In this analysis, the Higgs boson is reconstructed in its decay channel to a bottom-quark-antiquark pair. The anomalous production of single top quarks via FCNC is considered as well as the anomalous decay of top quarks to a Higgs boson and a charm quark or an up quark in top-quark-antiquark pair-production events.
- Search for the production of a single top quarks via FCNC couplings between a top quark and a gluon.
- Unfolding of distributions of observables sensitive to effects of colour reconnection in top-quark-antiquark pair-production events. In this analysis, di-lepton electron-muon events are selected. The aim is testing and constraining systematic uncertainties due to modeling of colour reconnection in parton-shower event generators. These uncertainties play an important role in the measurement of the top-quark mass.
- Generic search for physics beyond the standard model using autocencoders.
Look at this interesting collection of top-quark physics literature.
Detector development and upgrade of the ATLAS pixel detector
- Development of firmware and software for the readout electronics of the new ATLAS Pixel detector for the high-luminosity phase of the LHC. The installation of the new detector is planned for 2026. The planned bandwidth is several Gb/s per transmission line. To meet the extraordinary challenges in data rates when calibrating the detector solutions based on distributed computing are investigated.
- Maintenance of firmware of the readout electronics of the current ATLAS Pixel detector. Preparations are ongoing to meet the operation conditions during Run 3 of the LHC in the years 2021 to 2024.
- Development of a production setup for loading of hybrid pixel modules on local support structures. During the production phase of the new ATLAS Pixel detector it is foreseen to load several hundreds of modules in Wuppertal.
- Development and construction of a experimental setup to investigate the dynamics of fluid CO2 in the dual phase cooling loops of the new ATLAS Pixel detector.
- Development of an interlock system of the new Inner Tracker (ITk) of ATLAS. The ITk will consist of a new pixel detector and a new silicon microstrip detector. The development in Wuppertal includes the design and production of printed circuit boards, firmware and crates.
- Studies on the development of detectors based on Perowskit materials.