Oct 16 – 20, 2016
Europe/Zurich timezone

The aSPECT experiment – current status of the analysis

Oct 18, 2016, 6:22 PM


Mr Alexander Wunderle (Johannes Gutenberg-Universität Mainz)


The aSPECT retardation spectrometer measures the beta-neutrino angular correlation coefficient a in free neutron beta decay. This measurement can be used to determine the ratio g_A/g_V of the weak coupling constants, as well as to search for physics beyond the Standard Model. In spring/summer 2013 aSPECT had a successful beam time at the Institut Laue-Langevin. The goal of this beam time is to improve the current uncertainty of a from to about 1%. The data analysis is in its final stage and will be finished soon. In order to achieve an uncertainty of 1% the systematics of aSPECT have to be understood accordingly. This understanding is gained via systematic tests and measurements of a with different parameter settings for the spectrometer during the beam time. Additionally, auxiliary measurements have been performed to determine the effect on the systematics, e.g. work-function fluctuations of the electrodes, the magnetic field ratio of the spectrometer and detailed tests of the detector electronics. In this poster an overview of these auxiliary measurements and their results is given. Further, the analysis of various systematics, e.g. potential saturation of the DAQ, pile-up, background from residual gas, energy dependent projection of decay protons, and the influence of these systematics on a is shown. Additionally, the concept of an analysis using a multi-dimensional fit is explained.

Primary author

Mr Alexander Wunderle (Johannes Gutenberg-Universität Mainz)


Mr Christian Schmidt (Johannes Gutenberg-Universität Mainz) Mr David Stipp (Johannes Gutenberg-Universität Mainz) Mr Edward Beckmann (Johannes Gutenberg-Universität Mainz) Dr Ferenc Glück (Karlsruher Institut für Technologie) Dr Gertrud Konrad (TU Wien, Atominstitut, Austria) Mr Jan Haack (Johannes Gutenberg-Universität Mainz) Mr Jan Kahlenberg (Johannes Gutenberg-Universität Mainz) Mrs Kim Ross (Johannes Gutenberg-Universität Mainz) Dr Marcus Beck (Helmholtz-Institut Mainz and Johannes Gutenberg Universität Mainz) Dr Martin Simson (Institut Laue-Langevin) Prof. Oliver Zimmer (Institut Laue Langevin) Mr Rishi Horn (Johannes Gutenberg-Universität Mainz) Dr Romain Maisonobe (Institut Laue-Langevin) Mr Romain Virot (Institut Laue-Langevin) Torsten Soldner (Institut Laue Langevin) Prof. Werner Heil (Institute of Physics)

Presentation materials