According to De Vries, precision research offers an alternative route in particle physics, where large particle accelerators usually play a key role. However, the largest accelerators have not yet discovered any truly new phenomena that extend beyond the current Standard Model.

This leaves some major questions unanswered: why, for example, there is no antimatter in the universe, or why neutrinos have mass. Subtle deviations in the various beta decay measurements could offer new clues for theorists, De Vries claims.

According to De Vries, low-energy experiments, through greater precision, can be effectively linked to several mysteries in high-energy physics and cosmology. To test this idea, he has received a €2 million Consolidator Grant from the European Research Council (ERC) for his CRUNS project.

The grant will allow him to establish a team of two postdocs and three PhD students. Over the next five years, they will develop new theoretical methods to calculate the various versions of beta decay much more precisely. This will allow for better detection of any deviations from theory in experimental results.

De Vries focuses on beta decay and the electron dipole moment. Beta decay is the radioactive decay of neutrons in atomic nuclei, producing a proton and an electron. Three forms of beta decay are known in theory, which in his proposal De Vries calls common, rare, and unseen.

In common beta decay, a neutron decays into a proton and an electron, plus an anti-electron neutrino. In the extremely rare beta decay, two neutrons decay simultaneously, one of the slowest processes ever measured in a laboratory. Unseen is the so-called neutrinoless double beta decay, which exists in theory but has never been measured.

Numerous experiments worldwide study beta decay without accelerators. Nikhef is involved in the XENONnT experiment in Italy, which, in the context of the hunt for dark matter, also examines double beta decay. In Groningen, an experiment is being built to measure the electron dipole moment with extreme precision; De Vries is providing the theoretical calculations for this.