Calculating Particle Decay Mass and Velocity

[Chris T]

Homework Statement

A particle of unknown rest mass, M, traveling at an unknown speed, v, decays to an electron, a positron and a photon with the following four-momenta: pe x pe y pe z Ee/c pp x pp y pp z Ep/c pγ x pγ y pγ z Eγ/c
Write down an expression for M in terms of these four-momenta. These four momenta are measured in a detector (in units of GeV/c) to be, respectively,: 0 50 0 50 , 0 −50 0 50 , 0 0 100 100 where the mass of the electron is neglected.

Homework Equations

Calculate M and v.

The Attempt at a Solution

 

[PeterDonis]

Chris T, you need to make some attempt at a solution. To start, you might think about what equations would be relevant. Is there an equation that relates the energy and momentum of a particle with a given rest mass?