Humboldt-Universität zu Berlin - Mathematisch-Naturwissen­schaft­liche Fakultät - Experimentelle Elementarteilchenphysik

Bachelor- u. Masterprojekte der AG Issever (HEP)

Bachelorprojekte Masterprojekte Issever HEP

Master Thesis Topics

  • Phenomenology studies for diHiggs to 4b sensitivity studies

    In the context of the ERC HiggsSelfCoupling project we have this phenomenology study that aims to improve the sensitivity of our searches for diHiggs to 4b events and also the measurement of the Higgs self-coupling paramemters. In this study you would work with neural network algorithms and simulated collision events.

  • Development of novel flavour tagging techniques using neural network algorithms

    This project would involve working with Prof. Todd Huffman at Oxford University and Dr. Spyros Argyropoulos at Freiburg University on novel flavour tagging techniques by modifying or developing an existing Neural network that is used to “tag” high energy Jets generated at the Large Hadron Collider in the ATLAS experiment at CERN.

    Starting from a framework that contains the information of hit multiplicities in jets, the student would study the impact of additional hit variables (e.g. the probability of the hit to originate from more than one charged particles) on the performance of the ATLAS Deep Learning algorithms for b-tagging. The existing framework needs to be retrained with more simulations, but in addition we would like the student to study expanding these “hit-based” additions to the Neural Network to include clusters that appear in new regions of the detector that have not been previously considered. Specifically the outer SCT strip tracker and also the pixel disk detectors. We would also like to explore the possibility of using a Graphical Neural Network where the pixel position, but also the energy and angle of the highest energy track in the jet provide a kind of “picture” that GNN systems seem particularly suited to recognizing patterns. This last depends upon whether the appropriate framework can be established and how quickly the first parts of the project progress. Since this project will be in collaboration with colleagues in the UK the student should be fluent in English. Experience in programming is also desireable.  

Bachelor Thesis Topics

  • Preparatory studies on proton-Oxygen collisions at the LHC

    One of the most important sources of uncertainties in studying cosmic rays with Cherenkov telescopes is the modelling of hadronic interactions of an incoming cosmic particle and an atomic nucleus in Earth's atmosphere. In the upcoming Run 3 of the LHC a unique opportunity presents itself to explore exactly those interactions under laboratory conditions by studying collisions of protons and Oxygen nuclei with the help of the ATLAS detector and other detectors in the forward region of ATLAS. The goal of this Bachelor project will be to study adequate observables with which individual hadronic processes can be separated and also isolated from background processes. This should enable us to measure the cross sections of those processes and the energy spectra of the created particles, as soon as the p-O collision data will have been taken at the end of run 3. Moreover, the detectors' positions in the forward region and the beam optics of the LHC should be optimized for such a measurement.