Hartmut Abele


Univ. Prof. Dipl. Phys. Dr. Hartmut Abele

Technische Universität Wien, Stadionallee 2, 1040 Wien

Tel.: +43-1-58801-141447

e-mail: abele@ati.ac.at

web:  ati.tuwien.ac.at/…

The qBounce experiment at the Atominstitut.

The structure and nature of weak interactions are addressed by precise spectroscopy measurements. The working group concentrates on angular correlation measurements in neutron beta-decay. Recent measurements include the coefficients A (β-asymmetry parameter), coefficient B (neutrino-asymmetry parameter) and a first time measurement of coefficient C (proton-asymmetry parameter) with increasing accuracy. All semileptonic cross-sections used in particle physics and astrophysics must be calculated from these measurements. Correlation coefficient results enter in the prediction for the energy consumption in the sun via the primary reaction in the pp-chain and the solar neutrino flux, the light elements in the primordial nucleosynthesis, and the neutron star formation. They also are also used for the calibration of neutrino detectors, and an input for the unitarity check of the CKM matrix. Correlation coefficients determine the Standard Model parameters describing neutron decay and test speculative models beyond the Standard Model, which involve left-right symmetry, fundamental fermion compositeness, new particles, leptoquarks, supersymmetry, supergravity and many more.

Quantum states in the Earth’s gravitational field can be observed, when neutrons fall under gravity. The group of Abele uses ultra-cold neutrons, which are reflected and vertically trapped in a gravitational cavity above a horizontal mirror. In 2002, the lowest stationary quantum state of neutrons in the Earth’s gravitational field was clearly identified by the group of Abele and collaborators. In a new setup in 2008 and 2009, the group has measured the spatial probability distribution of the corresponding Schrödinger wave packet in the gravity potential with a spatial resolution of about 1.5 μm. With this new technique the way is paved for new and precise searches for short-ranged non-Newtonian gravity searches.