PRISMA+ postdoc René Reimann receives prize for his doctoral thesis

Dr. René Reimann has been working as a postdoc in the work group led by Prof. Martin Fertl since March 2020. He has now been awarded the GNN (The Global Neutrino Network) dissertation prize for his doctoral thesis at RWTH Aachen University.

He was nominated by his doctoral supervisor at Aachen, Prof. Christopher Wiebusch. Entitled “Search for the Sources of the Astrophysical High-Energy Muon-Neutrino Flux with the IceCube Neutrino Observatory”, René Reimann scoured the entire northern sky for the origin of high-energy neutrinos: The measurements were taken in 2013 at the IceCube Neutrino Observatory at the South Pole. “At the time, IceCube opened a whole new window to the universe,” René Reimann explains. “Although cosmic radiation has been measured for over a century, its sources and the underlying acceleration mechanisms remain unanswered questions. The perfect messenger particle to answer this question is the neutrino – which we can detect in the polar ice of the South Pole using the sophisticated detectors at IceCube.”

A press release from 2013 stated: “After more than a decade of intense searching, we can now announce that we have found neutrinos that were very probably generated in the vast expanses of outer space.” The researchers suspected that high-energy neutrinos may be generated in the proximity of black holes and are subsequently accelerated to acquire their extraordinary energies.

In his doctorate, René Reimann tested numerous celestial positions in an attempt to determine whether they could be the source of the high-energy neutrino flow which was observed at the time and repeatedly confirmed, having also been measured over the following years. For this purpose, he evaluated the eight years’ worth of data that IceCube had collected and significantly improved on previous analyzes. “As a result of my work, I could not assign a source to neutrinos, but I could question some sources that are discussed in the literature.”

In Mainz, René Reimann’s work also remains devoted to neutrinos. At least in part, as he is involved in two experiments, one of which – the Project 8 Experiment – aims to measure the absolute neutrino mass. He is also involved in the Muon g-2 Experiment, which hopes to measure the anomalous magnetic moment of the muon with an unprecedented accuracy of 0.14 ppm (140 to 1 billion). Both experiments have a common feature that fascinates René Reimann: they want to question the current standard model of particle physics and put it to the test. “In the case of the anomalous magnetic moment of the muon, there is a deviation between the current experimental value and the theoretical value calculated on the basis of the standard model,” René Reimann explains. “With the highly accurate Muon g-2 Experiment, we want to find out whether this deviation is real or merely a result of systematic uncertainties between theory and experiment.” According to René Reimann, the masses of neutrinos do not fit into the current standard model either: “Both experiments therefore offer a very exciting starting point for testing the shortcomings of the standard model.” For René Reimann, this the most important reason to spend his time as a postdoc at the PRISMA+ Cluster in the group led by Martin Fertl.