structural:scholar_edition
Tau decay

The tau is the only lepton that can decay into hadrons – the masses of other leptons are too small. Like the leptonic decay modes of the tau, the hadronic decay is through the weak interaction.

The branching fractions of the dominant hadronic tau decays are:

In total, the tau lepton will decay hadronically approximately 64.79% of the time.

The branching fractions of the common purely leptonic tau decays are:

The similarity of values of the two branching fractions is a consequence of lepton universality.