Lepton Universality Test of Extra Leptons using Hadron Decay

Understand

We study the flavor universality of the lepton couplings with the W and Z bosons.

• Currently, it is constrained by the electroweak precision observables.
• We focus on the leptonic decay of the pion.
• It is shown that the decay is expected to have a comparable or better sensitivity to the lepton-flavor universality in the near future.