ohhhhhh i think for the first invariant i just make p^2=0 because in the rest frame there is no momentum…i'm dumb…
as for the invariant on the right side of the equation i think i use p^2 as p=(e/c)cos30 to find the x component since the y component cancels out anyway, so the p would be...
Homework Statement
A meson (elementary particle) decays into two photons, each of energy 150MeV in its rest frame. Find the mesonic kinetic energy in the case of a symmetric decay in flight with an angle of 60degrees between the photon momenta (30 degrees for each particle on each side of the...