A pi meson of mass mπ move with speed uin the positive y direction in frame S with parametersβu = u/c and γu = (1 - βu2)-1/2. The pion decaysinto two gamma rays. An observer S' moves in the positive xdirection with speed v = βc (γ = (1 -β2)-1/2) and detects the twophotons.
A. Compute the sum of the x components of momentum in S' for thephotons.
B. Compute the combined energy of the two photons in S'?