# Particle Collision

1. May 27, 2008

### Air

1. The problem statement, all variables and given/known data
The results of particle collisions are observed using particle detectors. Sometimes the products of these collisions are themselves unstable and decay to give further particles; the products of decay can be photons.

In one collision, a stationary $\pi^\circ$ meson is produced which then decays to give two gamma ray photons. The rest mass of the meson is $135 \ MeV/c^2$.

$\pi ^\circ \rightarrow \beta + \beta$​

Calculate the wavelength of each photon.

2. Relevant equations
$E = hf = \frac{hc}{\lambda}$

3. The attempt at a solution
How can I find $E$? I can carry on from that point but I don't know which equation to use to find $E$?

Last edited: May 27, 2008
2. May 27, 2008

### gendou2

The energy of the stationary meson is calculated using E = mc2

Epi = mpi*c2 = 135 MeV / c2 * c2 = 135 MeV

Last edited: May 27, 2008