Not yet reviewed by Pith; the record is open.

Neutrinos are the most elusive particles in our universe. They have masses at least one million times smaller than the electron mass, carry no electric charge, and very weakly interact with other particles, meaning they are rarely captured in terrestrial detectors. Tremendous efforts in the past two decades have revealed that neutrinos can transform from one type to another as a consequence of neutrino oscillations---a quantum mechanical effect over macroscopic distances---yet the origin of neutrino masses remains puzzling. The physical evolution of neutrino parameters with respect to energy scale may help elucidate the mechanism for their mass generation.