UW News

Center for Experimental Nuclear Physics and Astrophysics


August 10, 2023

Muon g-2 doubles down with latest measurement, explores uncharted territory in search of new physics

A particle physics experiment decades in the making — the Muon g-2 experiment — looks increasingly like it might set up a showdown over whether there are fundamental particles or forces in the universe that are unaccounted for in the current Standard Model. On Aug. 10, the international team of scientists behind Muon g-2 — pronounced “g minus 2” — released the world’s most precise measurement yet of the anomalous magnetic moment of the muon. Calculating the muon’s magnetic moment at a high precision will indicate whether it is interacting solely with the particles and forces known today, or if unknown particles or forces are out there.


February 23, 2022

A new upper limit on the mass of neutrinos

An international research team, including scientists from the University of Washington, has established a new upper limit on the mass of the neutrino, the lightest known subatomic particle. In a paper published Feb. 14 in Nature Physics, the collaboration — known as the Karlsruhe Tritium Neutrino Experiment or KATRIN — reports that the neutrino’s mass is below 0.8 electron volts, or 0.8 eV/c2. Honing in on the elusive value of the neutrino’s mass will solve a major outstanding mystery in particle physics and equip scientists with a more complete view of the fundamental forces and particles that shape ourselves, our planet and the cosmos.


April 7, 2021

First results from Muon g-2 experiment strengthen evidence of new physics

A picture of the giant magnetic ring at the heart of a particle physics experiment

The first results from the Muon g-2 experiment hosted at Fermi National Accelerator Laboratory show fundamental particles called muons behaving in a way not predicted by the Standard Model of particle physics. These results confirm an earlier experiment of the same name performed at Brookhaven National Laboratory. Combined, the two results show strong evidence that our best theoretical model of the subatomic world is incomplete. One potential explanation would be the existence of undiscovered particles or forces.


March 26, 2018

Underground neutrino experiment sets the stage for deep discovery about matter

Copper housing for a stack of germanium detectors.

In a study published March 26 in Physical Review Letters, collaborators of the MAJORANA DEMONSTRATOR have shown they can shield a sensitive, scalable 44-kilogram germanium detector array from background radioactivity. This accomplishment is critical to developing a much larger future experiment to study the nature of neutrinos.