Franziska Hagelstein has been awarded a Swiss National Science Foundation Ambizione grant with PSI as host institution. She joined the particle theory group (NUM, Laboratory of Particle Physics LTP) in October 2020. In the near future she will be accompanied by a PhD student.
The research of Franziska Hagelstein focuses on hadronic corrections to low-energy muon anomalies. One of the goals of her research is to reduce and reliably determine the dominant uncertainties in precision observables as e.g. the anomalous magnetic moment of the muon and the extraction of the proton radius in muonic hydrogen. The anomalous magnetic moment of the muon shows a deviation of more than 3 standard deviations from the SM prediction. Moreover, the proton radius determined from muonic hydrogen at PSI within the CREMA experiment established a significant difference of more than 5 standard deviations from former experimental measurements of electronic hydrogen and electron-proton scattering experiments. The work on the magnetic moment of the muon will elaborate on a complementary approach to determine the hadronic effects and might eventually help to reduce the uncertainties originating from light-by-light scattering contributions. The same methods can be applied to the proton structure in hyperfine splitting measurements in muonic hydrogen.
Franziska Hagelstein obtained her PhD from the Johannes Gutenberg University of Mainz in 2017. After three years as postdoc at the University of Bern she joined the LTP theory group of PSI in 2020 with her SNF Ambizione grant.