Rotational Invariance and angular distributions: A spin-1 particle is polarized such that its spin direction is along the +z axis. It decays, with total decay rate Γ, to π+π−. What is the angular distribution, dΓ/dΩ, of the π+? Note that the π± has spin zero. What is the angular distribution if the initial spin projection is zero along the z-axis? Minus one? What is the result if the initial particle is unpolarized (equal probabilities for all spin orientations)?