Low Energy Precision Physics

NEWS: the new UCN source SuperSUN is now operational at the ILL in Grenoble!

We perform precision tests of the Standard Model, search for new physics, and develop new measurement methods at the interface of particle physics, atomic physics, and nuclear physics. We also work closely with theorists, especially on the implications of EDM constraints in particle phenomenology. Current themes include:

Permanent electric dipole moments, or "EDMs"
Ultracold neutron science, sources, and detectors (see also: HEiKA project 2024)
Optical excitation of noble gases
Precision magnetometry and low magnetic fields
Global analysis in low energy particle physics (see a recent preprint)

Our approach in general is very complementary to high-energy collider physics: rather than exciting high-energy processes directly, we look for their signature in virtual effects or through very weak couplings. In some cases this means that our experimental sensitivity can reach extremely high mass scales (PeV or more). This complementarity is illustrated below:

While both "high energy" and "high precision" searches can be sensitive to new physics signals from the same sources, these signals enter experiments in very different ways. High-energy searches are typically sensitive to specific channels, for example seeking to directly produce a new particle. Low-energy experiments more typically measure very subtle effects arising indirectly from new degrees of freedom, and collect contributions from many possible sources like a "lightning rod" for new physics processes. While these approaches are often aligned, respectively, with the labels of "energy frontier" (red vertical arrow) and "intensity frontier" (green horizontal arrow) research, it is important to understand that collider searches can also measure virtual processes with high precision ...and low-energy experiments can also constrain very high mass scales.