# The lorentz boost of the CM frame w/ respect to the lab frame

Hi i have a problem with some work.

a muon type neutrino interacts with a stationary electron, producing a muon and electron type neutrino. I have calculated the CM energy but now need to calculate gamma, the lorentz boost.

γ=(Eν/2me)^1/2

How do i show this? the info i have is that β=P/E and Ev and me are the obvious relevant energy / mass. Any help towards the solution for gamma would be appreciated.