Electron-positron pair creation by weak interaction?

[x_ferrari_x]

Hello,
Im trying to find out if, since an electron positron pair can anhillate to produce a muon-anti muon pair by the weak interaction, can the same thing occur for the production of an electron/anti-electron pair? Or would it just happen by the electromagnetic force? Or both, with the weak being supressed? And are the photons/ Z0 bosons involved real or virtual?
I feel as if I am asking a question I should know the answer to and being silly, but any help would be appreciated!
Thanks!

 

[malawi_glenn]

e+e- -> e+e- via Virtual Z^0 is ok.

 

[jtbell]

It's simply very rare because the mass of the Z_0 suppresses the cross section. I think some experiments do study contributions from Z_0 exchange in certain processes (maybe even e+e- scattering), as tiny corrections to a pure photon-exchange model.

 

[x_ferrari_x]

Thanks, that's very helpful!

 

[hamster143]

The technical term for this process is "Bhabha scattering":

http://en.wikipedia.org/wiki/Bhabha_scattering

If the electron and the positron are nearly at rest, Z contribution is significantly suppressed because the intermediate virtual Z is way off mass-shell. At high energies, both are important. At CM ~ 90 GeV, Z exchange will most likely dominate.

 

[jtbell]

At CM ~ 90 GeV, Z exchange will most likely dominate.

Indeed, the old Large Electron Positron (LEP) collider was originally designed for a CM energy in that range, specifically to produce the Z_0.