| Popis: |
We discussed the photoproduction of charged particles in pairs a¯ a (a = e, µ, π) as well as double photon emission processes off an electron ac- counting for the polarization of colliding particles. In the kinematics when all the particles can be considered as massless, we obtain com- pact analytical expressions for the differential cross sections of these processes. These results are applied to special cases of pair production by circular and linear polarized photons. We consider the lowest order inelastic QED processes in photon- electron interaction at high energies.We take into account the polar- ization of colliding photons and electron and consider the experimental setup,when the polarization of final particles is not measured.The in- terest to such kind processes is twofold. Linear e + e − high energy col- liders(planned to be arranged (1, 2)) provide the possibility (using the backward laser Compton scattering) to obtain the high energy photon- electron colliding beams. The problem of calibration as well as the prob- lem of important QED background are to be taken into account for this kind of colliders.The second important reason to investigate such reac- tions is the well known possibility to use the photoproduction of leptons pairs as a polarimeter process(see,for instance, (3) and references therein) . Despite the fact that at high energy the bulk of particles are pro- duced at very small angles, experimentally it is much easy to detect the particles produced at large angles.Thus we investigate the kinematic in which all invariants determining the matrix elements of the processes un- der consideration will be much bigger than masses of particles involved in the reaction. |
