Measuring the Beam Polarizations and the Luminosity at Photon-Photon Colliders

Abstract

We present methods to measure the beam polarizations and the luminosity of $γγ$ colliders at TeV energy scale. The beam polarizations of a $γγ$ collider can easily be monitored by comparing the numbers of events of the processes $γγ$ $\rightarrow$ $\ell^+ \ell^-$ and $γγ$ $\rightarrow$ $W^+ W^-$, where $\ell$ means $e$ or $μ$. The luminosity of a $γγ$ collider is also measurable by the event rate of $W$ boson pair productions and the light lepton pair productions.