# Particle physics question: beam energy

1. Oct 23, 2007

### quark.antiquark

1. The problem statement, all variables and given/known data
Tertiary neutrino and muon beams can be formed using pion -> muon + neutrino decays from a high intensity, high energy secondary pion beam. Consider a secondary pion beam of 100 GeV/c momentum and assume that the neutrinos have a mass of a few eV. Within what angular cone are the muons confined in the lab? What is the range of muon energies available in the lab?

2. Relevant equations
(None provided)

3. The attempt at a solution
I'm really not sure how to approach this one. The text gives a formula for the angular deflection of secondary beams in terms of the momentum of the original beam and the dimensions and potential of the separator. The problem is, we're not given any of this information. Is there another method to find the angle?

2. Oct 24, 2007

### Meir Achuz

You can take the neutrino as massless.
Find the muon momentum and energy in the center of mass system.
Take the angle for the muon momentum at 90 degrees to the pion flight direction.
Lorentz transform the muon momentum.