Possibility To Study Photon Scattering By Proton In The Reaction e+p -> e+p+gamma

Abstract

A theoretical possibility to determine the proton Compton scattering cross section from the reaction $ep\rightarrow ep\gamma$ is studied in the kinematics with a small transversal momentum transfer in the electron leg. With the exception of the region of forward photon directions and extreme photon energies close to the maximum ones or zero, registration of the particles $\gamma$ and $p$ in the final state can enable one to distinguish the sub-process of the Compton scattering from the electron bremsstrahlung background and, owing to complete kinematical reconstruction of each individual event, measure in detail energy and angular dependence of the $\gamma p$-scattering cross section. The count rate expected with a storage ring like NEP having luminosity $L \approx 2 \cdot 10^{35}$ cm$^{-2}\cdot$ sec$^{-1}$ as projected is $\approx 10^3$ events/hour. Such measurements might help to determine proton polarizabilities with high statistical accuracy.