DFG Priority Program SPP 1491

Precision experiments in particle- and astrophysics with cold and ultracold neutrons

The Priority Program SPP 1491 of the DFG deals with precision measurements in particle physics and astrophysics using as specific tool: the neutron. New high intensity sources of ultracold neutrons and neutron decay products are coming into operation within the next years, potentially exceeding the performance of current generation neutron sources by many orders of magnitude. Within this Priority Program these new technologies are exploited to address some of the unsolved questions of modern science: the nature of the fundamental forces and underlying symmetries, as well as the nature of the gravitational force at very small distances. New facilities and technological developments now open the window for significant improvement in precision by 1-2 orders of magnitude. This allows to probe these questions in a complementary way to LHC based experiments or even constitute a unique way. The research program focuses on four priority areas, which are directly related to specific physics/astrophysics issues. A detailed description of the priority areas can be found here.

Priority area A

CP-symmetry violation and particle physics in the early universe (addressed mainly by the search for the neutron electric dipole moment)

Priority area B

The structure and nature of weak interaction and possible extensions of the standard model (addressed mainly by precise beta decay studies of the neutron)

Priority area C

Relation of gravitation and quantum theory (probed by investigations of low energy bound states in the gravitational field)

Priority area D

Charge quantization and the electric neutrality of the neutron (probed by a precision test of the neutron's electric charge)

Priority area E

New measuring techniques

Particle detection
Magnetometry
Neutron optics