Muon Department


Fermilab is launching a suite of experiments that hunt for physical anomalies and look for discrepancies from the predictions of the Standard Model, our theoretical framework describing fundamental interactions. Scientists working on the Muon g-2 and Mu2e experiments use beams of muons to do this. The muon is a heavy version of the electron that can be produced in particle interactions.

The Muon Department is home for Fermilab scientists, staff, and users from academic institutions around the world, working on muon experiments.

The Standard Model is silent on the prospect of lepton conversions, such as neutrino oscillation or muon-to-electron conversions. Theorists have patched the Standard Model to include the shape-shifting behavior of neutrinos, but there is no deep understanding of why or how these transformations happen. Muon-to-electron conversions go beyond the Standard Model entirely to the realm of New Physics models.

Both the Muon g-2 and Mu2e experiments are several years away from taking data. Currently, the infrastructure for the Muon Campus is being developed.

Muon g-2


The Muon g-2 experimenters will examine the precession of muons that are subjected to a magnetic field. The main goal is to test the Standard Model's predictions of this value by measuring the precession rate experimentally to a precision of 0.14 parts per million. If there is an inconsistency, it could indicate the Standard Model is incomplete and in need of revision.



The Mu2e experiment will also use an intense beam of muons but will examine a property outside the understanding of the Standard Model: the possibility of a muon-to-electron conversion.