1 Property (T) and property (τ) 13 1.

To accommodate the 9 new experimental papers listed in the τ References for this edition, only a few changes were made to the τ Listings. There were new measurements of the τ charged-prong topological branching fractions by the DELPHI [1] and L3 [2] collaborations. Early measurements of these branching fractions tended to define charged tracks from K 0 S → π − π + decays as charged prongs, whil...

Theoretical study of anomalous decay mode τ → ωπππν is presented. Theoretical value of the branching ratio of τ − → ωπ − π 0 π 0 ν agrees well with data. The branching ratio of τ − → ωπ + π − π − ν τ is predicted. It is found that the vertices of a 1 ρπ and ωρπ play dominant role in these two decay modes. CVC is satisfied and there is no adjustable parameter.

The availability of large samples of τ leptons allows for searches of very rare (Standard Model forbidden) τ decay modes, which provide a sensitive probe for physics beyond the Standard Model (BSM). In recent years, very large samples of τ leptons have been made available by the high luminosity running of the two asymmetric B-factories PEP − II and KEK B, which, in light of the comparable size ...

Based on a 670 fb −1 data sample accumulated at the Belle detector, we have looked for a second-class current decays τ → πην and τ → πη (958)ν. First possible indications for the τ → πην decay are attained with a 2.4 significance corresponding to the branching fraction B(τ − → π − ην τ) = (4.4 ± 1.6 ± 0.8) × 10 −5 or B < 7.3 × 10 −5 at 90% confidence level. Also, the upper limit on B(τ − → π − ...