[Zurück]

H. Saul, H. Abele, D. Dubbers, M. Klopf, G. Konrad, P Lennert, B. Märkisch, H. Mest, A Pethoukov, L Raffelt, C. Roick, U. Schmidt, T. Soldner, X. Wang, D Werder:
"Angular correlation measurements in neutron beta decay with Perkeo III";
Vortrag: 12th Conference on the Intersections of Particle and Nuclear Physics, Vail (eingeladen); 19.05.2015 - 24.05.2015.

Within the standard model of particle physics, semileptonic weak decay is described by only two free parameters, the ratio of vector and axial vector couplings λ and the first element of the CKM-matrix Vud. Due to the absence of nuclear structure, neutron beta decay is an ideal probe to test the structure of the weak interaction.
Measuring the parity violating beta asymmetry A in polarized neutron decay is the most precise way of determining λ. More, further measuring the energy dependence of A allows to derive limits on non-standard interactions via the Fierz interference term, which is sensitive to scalar and tensor couplings. Combining results from different precision measurements of angular correlation coefficients could provide even stronger limits on these parameters.
In this talk we present the neutron decay spectrometer Perkeo III and details about the data analysis of the currently most precise measurement of the beta asymmetry. This measurement was carried out at the PF1B cold neutron beam line at the Institut Laue-Langevin. We also present the status of the currently ongoing campaign to measure the proton asymmetry C.