e+ e− → τ+ τ− at the threshold and beyond

The onset of e + e − → τ + τ − at threshold revisited

→ τ + τ − at the threshold and beyond

The excitation curve for the τ τ− production in electron positron annihilation near the threshold is revisited with the aim of updating and extending a previous work. We find that the corrections of the relative magnitude O(α) near the threshold are significantly contributed by the radiative modification of the Coulomb interaction between the τ leptons. The interpolation between the Coulomb eff...

Measurement of the branching fractions of the radiative leptonic τ decays τ → e γνν̄ and τ → μγνν̄ at BABAR

J. P. Lees, V. Poireau, V. Tisserand, E. Grauges, A. Palano, G. Eigen, B. Stugu, D. N. Brown, L. T. Kerth, Yu. G. Kolomensky, M. J. Lee, G. Lynch, H. Koch, T. Schroeder, C. Hearty, T. S. Mattison, J. A. McKenna, R. Y. So, A. Khan, V. E. Blinov, A. R. Buzykaev, V. P. Druzhinin, V. B. Golubev, E. A. Kravchenko, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, E. P. Solodov, K. Yu. Todyshev, A. J...

HU-TFT-92-50 POLARIZATION AND HANDEDNESS IN τ → a1ν → 3πν DECAY PRODUCED IN e + e − → τ + − ∗ τ

A Measurement of the τ − → e − ν̄ e ν τ Branching Ratio

The branching ratio for the decay τ → e−ν̄eντ has been measured using Z 0 decay data collected by the OPAL experiment at LEP. In total 33 073 τ → eν̄eντ candidates were identified from a sample of 186 197 selected τ decays, giving a branching ratio of B(τ → eν̄eντ ) = (17.81 ± 0.09 (stat) ± 0.06 (syst))%. This result is combined with other measurements to test e μ and μ τ universality in charged-c...