Beyond-the-Standard-Model Physics with Nucleons and Nuclei

Organizer(s) J. De Vries, E. Mereghetti, M. Piarulli, A. Walker-Loud
Location: Institute of Nuclear Theory (INT), University of Washington

In the next decade, an impressive experimental program will test the limits of the Standard Model (SM) and address the most pressing open questions in particle physics, from the nature of dark matter to the origin of neutrino masses, from the dominance of matter over anti-matter in the universe to the absence of strong CP violation and the large hierarchy between the electroweak and the Planck scale. Searches for beyond-the-SM (BSM) physics via low-energy precision experiments will play a crucial role in answering these questions, by looking, in particular, for deviations from symmetry patterns of the SM. Prominent examples involving nuclear systems are searches for lepton number violation via neutrinoless double beta decay, probes of CP violation via EDM experiments with nucleons, nuclei, and diamagnetic atoms, and DM direct detection. Other experiments look for proton decay, neutron-antineutron oscillations, non-standard charge-current interactions in neutron and nuclear β decays, CPT violation, neutrino-scattering experiments, and the list goes on.

These experiments are complementary to high-enery experiments such as the LHC or DUNE, and share the common feature of probing high-energy physics by using nuclear targets. Their interpretation involves physics on a large range of scales, from the eV and MeV scales of atomic and nuclear physics, to the GeV scale where hadronization takes place, all the way to the (multi-)TeV scale where BSM physics potentially originates. In the present unfortunate situation of no hints for any BSM signals at the LHC, low-energy precision searches, where significant improvements in sensitivity can be reached in relatively short time with relatively low costs, can take an even more prominent place in the future of particle physics.