Promotionsvortrag Physik: „Cosmic Rays and the Radio Neutrino Observatory Greenland (RNO-G)“

Ankündigung des Promotionsvortrags von: Frau Lilly Marie Pyras

Neutrinos are unique messengers, as they travel unimpeded over cosmological distances, point-ing back to their sources. As their production is tightly coupled to that of ultra-high energy cosmic rays (CR), they could help us understand the ultra-high energy universe. However, the expected neutrino flux at PeV energies is very low, and their detection is difficult due to their small cross section. Thus, large detection volumes of dense media are required. One such effort is the Radio Neutrino Observatory Greenland (RNO-G). When a neutrino interacts with a nucleus in the ice, it induces particle cascades that produce Askaryan emission. The hybrid design, consisting of an-tennas deep in the ice and just below the surface, also provides sensitivity to CRs, which improves background rejection for in-ice neutrino events.

The focus of this talk is on the precise estimation of CRs in RNO-G and the identification of at-mospheric muons originating from air showers. For this purpose, shallow detector component and the diode trigger are characterized. The digitizer boards and trigger are tested for functionality and performance prior to deployment. A detailed Monte Carlo study is performed, yielding an event rate of 3-10 CRs per day and 7 RNO-G stations. The energy threshold is around 1e17 eV and depends strongly on the trigger threshold. The performance of air shower detection has a direct impact on the neutrino identification, since ultra-high energy muons from air showers are a rele-vant background for in-ice neutrino detection. The muon rate is subject to large uncertainties, originating from hadronic interactions and the cosmic ray composition. A veto mechanism based on the detection of the parent air shower can be used to identify muons. A measurement of the atmospheric muon flux above PeV energies would provide a handle on the forward charm produc-tion in QCD.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.