Duiscuss the below:
Q1: A pion traveling at speed v decays into a muon and a neutrino, pi^- --> mu^- + v_mu. If the neutrino emerges at 90 degrees to the original pion direction, at what angle does the mu come off?
Q2: Particle A (energy E) hits particle B (at rest), producing particles C_1, C_2, ... A + B --> C_1 + C_2 + ... + C_n. Calculate the threshold (i.e., minimum E) for this reaction, in terms of the various particle masses.