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G. Konrad, J. Erhart, H. Fillunger, Ch. Gösselsberger, S Haas, P. Haiden, M. Horvath, E. Jericha, M. Klopf, C. Klauser, R. Maix, M. Moser, H. Saul, X. Wang, H. Abele:
"Exploring Fundamental Interactions via Neutron Decay";
Poster: Symposium "Research at European Neutron and Synchrotron facilities", Vienna, Austria; 11-11-2013 - 11-12-2013.

The Standard Model (SM) of particle physics is a theory that describes all interactions of suba-tomic particles, except those due to gravity. Although the SM explains a wide variety of ex-perimental results, it falls short of being a complete theory of fundamental interactions. Exten-sions of the SM are needed to explain its deficiencies.
Precision measurements of the parameters describing the beta decay of free neutrons address important questions in nuclear and particle physics, astrophysics, and cosmology [1, 2]. Our main emphasis is on the search for evidence of possible extensions of the SM and on searches for new symmetry concepts. In high energy physics with colliders, one directly searches for new particles, complementary to low energy physics with neutrons, where we indirectly probe their existence.
Together with scientists from the Universities of Heidelberg and Mainz, the TU München (all Germany), the Institut Laue-Langevin (ILL) in Grenoble (France), and the TU Wien, we propose to perform next generation high-precision meas-urements with the new instrument PERC (Proton and Electron Radiation Channel) [3]. In the search for new symmetries, measurements of correlation coefficients, inter alia a, A, B, C, and the Fierz in-terference term b, are of uttermost importance: uni-tarity of the CKM matrix, left-right symmetry, lep-toquarks, supersymmetry, etc. With the new facility PERC, several symmetry tests based on neutron beta decay data become competitive [4].
PERC is under development by an international collaboration [5]. Until PERC is built and installed at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Garching (Germany), we perform precision measurements of neutron decay observables with the existing aSPECT [6] and PERKEO III [7] experiments at ILL.
[1] H. Abele, Prog. Part. Nucl. Phys. 60, 1, 2008.
[2] D. Dubbers and M.G. Schmidt, Rev. Mod. Phys. 83, 11111171, 2011.
[3] D. Dubbers et al., Nucl. Instrum. Meth. 596, 238, 2008; see also: arXiv:0709.4440.
[4] G. Konrad, W. Heil, S. Baeßler, D. Pocanic, F. Glück, World Sci. ISBN 9789814340854, 660, 2011.
[5] G. Konrad et al. [PERC Collaboration], J. Phys.: Conf. Ser. 340, 012048, 2012.
[6] G. Konrad et al., Nucl. Phys. A 827, 529c, 2009; and references therein.
[7] B. Märkisch et al., Nucl. Instrum. Meth. A 611, 216, 2009.