Virtual Visit of the ILL
A quantum mechanics experiment to find an answer to one of the most fundamental questions of mankind:
A quantum mechanics experiment to find an answer to one of the most fundamental questions of mankind:
A permanent Electric Dipole Moment (EDM) of a quantum system like the neutron corresponds to the separation of charges along the spin direction. This doesn't sound spectacular, but it really is!
An EDM violates time reversal symmetry, a phenomenon deeply related to the asymmetry of matter and anti-matter in our Universe.
Discovering an EDM would thus change our understanding of the world fundamentally: any non-zero value would quite likely signal the manifestation of new physics beyond the Standard Model of Particle Physics.
In fact we don't just look only at the neutron itself, there is a lot happening around it -- including possible new and yet undiscovered "virtual" particles. These virtual particles can have lots of mass, as was typical in the Universe within picoseconds after the Big Bang. If we find them, we learn something important about the very early Universe.
But the measurement is difficult: PanEDM thus exploits a world-leading magnetically shielded environment and a conceptually new source of extremely low-energy "ultracold" neutrons that can be trapped for many minutes. During this long time, an extremely precise magnetic resonance procedure is performed, called Ramsey’s method of separated oscillating fields. With this approach one can identify tiny deviations from the known laws of nature, artifacts from shortly after the Big Bang, and hints to explain why matter in the universe still exists today.
