1. The problem statement, all variables and given/known data consider a pion decaying into 2 photons. In the rest frame of the pion, the two photons must emerge back-to-back photons are equally likely to emerge in any direction. determine the rest frame angular distribution of the emerging photons. 2. Relevant equations ΔP=f(θ)Δθ is the probability that a photon emerges with polar angle θ within some infinitesimal interval Δθ in the angle, and f(θ) is the rest frame angular distribution. 3. The attempt at a solution in the pion frame, the photons emerge back to back, and since there is no preferred decay direction, the probabilities of a photon emerging in any direction are the same. so f(theta) is a constant?