ABSTRACT
Particle physics tries to examine structure and strength of particle interactions and particle properties. Traditionally, it is associated with high energy physics working in the energy range of presently GeV and TeV. In contrast, our experiment was done with cold neutrons whose energies are even much lower than those of ordinary gas molecules at the other end of the energy spectrum. In the Standard Model of elementary particle interactions the fundamental fermionic constituents of matter are leptons and quarks found in three generations. In the decay of free neutrons a d-quark couples to a u-quark and the electron to an electron-antineutrino via a W-Boson exchange. This is a simple process where all particles of the first family are present. It allows to derive precise information about the first generation of the Standard Model and to access a number of interesting questions in particle physics, for example
• the ratio of the coupling constants X = (beta asymmetry A) • the quark mixing and the unitarity of the CKM matrix (A and neutron lifetime r) • the universality of the electroweak interaction (A and r) • the origin of parity violation and the proposed existence of right handed currents
(neutrino asymmetry B) • a violation of time reversal invariance beyond the Standard Model (triple correlations D
and R [1]) In all these fields important progress has been made in the last few years.
