Standard Model and Beyond · Problem 7.11

The Standard Electroweak Theory

Physics — Particle Physics · tau-decay-to-pion

Problem

Calculate the predicted rate and the angular distribution of the π−\pi^- with respect to the τ\tau spin direction for τ−→π−ντ\tau^- \to \pi^- \nu_\tau in the Fermi theory. Show, using the measured lifetime ττ=2.9×10−13\tau_\tau = 2.9 \times 10^{-13} s, that it leads to a branching ratio in agreement with the observed value of 11\%. Neglect mπm_\pi.

Browse the problem library