Finding kinetic energies of particles in center of mass frame from decay

[gnulinger]

Homework Statement

http://i.imgur.com/VVVAl.png

Homework Equations

K = mc^2/(1 -v^2/c^2)^(1/2) - mc^2
E = ((pc)^2 + (mc^2)^2)^(1/2)

The Attempt at a Solution

I don't know how to find the kinetic energies of the particles in the center of mass frame. I thought that they should just be exactly half the energy released in the decay from 498MeV to 140MeV (i.e. 179MeV), but that is wrong.

 

[Mike Pemulis]

Two pions are created, not one.

 

[gnulinger]

Thanks. I had just been working on the problem for a while and I was stuck in a rut.