Homework Help: Particle Physics - decay of a neutral pion

1. Jan 28, 2014

tableshark

Particle Physics -- decay of a neutral pion

1. The problem statement, all variables and given/known data

Consider the decay of a neutral pion that has a momentum of 10 GeV/c into two photons. What is the minimum energy that a photon from this decay can have? In terms of the pion mass and pion momentum. What about Maximum Energy too?

2. Relevant equations

E^2= p^2 c^2 + m^2 c^4
and Rest energy of neutral pion is 135 MeV/c2

3. The attempt at a solution

Think it would start out as energy conservation like
E(before)= E(after)
E(pion)= E(photon) + E(photon)
γmpionc^2= 2Ephoton
10,135 MeV= 2Ephoton
5,068 MeV= Ephoton

2. Jan 28, 2014

vela

Staff Emeritus
You're assuming the energy is split evenly between the two photons, but that's not generally the case in the lab frame.

Try considering what happens in the pion's rest frame. In what direction does a photon have to move so that it will have the most energy in the lab frame?