If dark matter exists, then where are the particles?
This single question threatens to topple the standard cosmological model, known as the LCDM model. The CDM stands for cold dark matter, and according to the model makes up nearly 85% of matter in the universe. It should be everywhere, and all around us, and yet every single search for dark matter particles has come up empty. If dark matter particles are real, we know what they are not. We don’t know what they are.
At the Fermi National Accelerator Laboratory (aka. Fermilab), an international team of scientists is conducting some of the most sensitive tests of the Standard Model of Particle Physics. The experiment, known as Muon g-2, measures the anomalous magnetic dipole moment of muons, a fundamental particle that is negatively charged (like electrons) but over 200 times as massive. In a recent breakthrough, scientists at Fermilab made the world’s most precise measurement of the muon’s anomalous magnetic moment, improving the precision of their previous measurements by a factor of 2.