Dr. Gertrud Konrad (TU Wien): "Search for new physics through precision measurements of neutron beta decay"

Friday 13 Dec 2013, 09:00 → 09:30 Europe/Berlin

Exzellenzcluster Universe (Seminar room K017)

Kurzvortrag im Rahmen einer Berufung Important questions in nuclear and particle physics, astrophysics, and cosmology are addressed with precision measurements of the parameters describing the beta decay of free neutrons. My research focuses on the discovery of new physics beyond the Standard Model and on searches for new symmetry concepts. The new user facility PERC will deliver neutron decay products under well-defined and precisely variable conditions. Depending on the parameters studied, the analysis of the extracted decay particles is performed with different and specialized detection systems. Our goal is to perform electron and proton spectroscopy on the sub-1‰ level. Such measurements require the almost complete suppression or the perfect knowledge of all systematic effects. With the aSPECT experiment, we experienced that residual gas and particle trapping are a severe problem in the analysis of decay protons. But, we developed solutions to overcome this problem, which I will discuss briefly. For electron and proton momentum spectroscopy at PERC, I will present a novel detection system based on the R×B drift effect. With the R×B spectrometer, we plan to find the so far not observed and in the Standard Model forbidden Fierz interference term b or to present new limits. The Fierz term b is measurable in decays of unpolarized neutrons, as a distortion of the beta spectrum. A non-zero value for b would be an indication of the existence of scalar or tensor interactions. Scalar or tensor couplings in turn would occur if yet unknown charged bosons or leptoquarks were exchanged instead of a W boson.