Question of Lorentz invariance in muon decay

Understand

Possibilities to test the Lorentz invariance of the weak interaction in muon decay are considered.

• We derive the direction-dependent muon-decay rate with a general Lorentz-violating addition to the W-boson propagator.
• We discuss measurements of the directional and boost dependence of the Michel parameters and of the muon lifetime as a function of absolute velocity.
• The total muon-decay rate in the Lorentz-violating Standard Model Extension is addressed.