Electron to Stationary Proton Collision

[PatrickStar]

Homework Statement

A 2 GeV electron is incident on proton (m_p * C^2 = 0.938 GeV) target at rest. Calculate the invariant mass of the electron-proton pair in the Center of Mass(CM) frame. Neglect the mass of electron which is much less than the proton mass.

Homework Equations

M = [P1 + P2)][/2]
M = gamma([m][/0])

The Attempt at a Solution

My first attempt was to calculate the mass through the second equation in relevant equations but I don't think that was correct. Because it went like this:

M = ([m][/0])/sqrt(1-(([v][/2])/[c][/2]) but I don't think that is necessarily the right step forward.
Any help would be much appreciated!

 

[vela]

Homework Statement

A 2 GeV electron is incident on proton (m_p * C^2 = 0.938 GeV) target at rest. Calculate the invariant mass of the electron-proton pair in the Center of Mass(CM) frame. Neglect the mass of electron which is much less than the proton mass.

Homework Equations

M = [P1 + P2)][/2]
M = gamma([m][/0])

The Attempt at a Solution

My first attempt was to calculate the mass through the second equation in relevant equations but I don't think that was correct. Because it went like this:

M = ([m][/0])/sqrt(1-(([v][/2])/[c][/2]) but I don't think that is necessarily the right step forward.
Any help would be much appreciated!

Can you elaborate on your attempt? I don't see what it has to do with any of the information given in the problem.

 

[PatrickStar]

Can you elaborate on your attempt? I don't see what it has to do with any of the information given in the problem.

Since posting this question I have realized that I must use the equation m^2=E^2-p^2 but I'm not really sure how to progress through the problem.