Coulomb phase corrections to the transverse analyzing power $A_N(t)$ in high energy forward proton-proton scattering

Abstract

Study of polarized proton-proton elastic scattering in the Coulomb-nuclear interference region allows one to measure the forward hadronic single spin-flip amplitude including its phase. However, in a precision experimental data analysis, a phase shift correction ${\delta }_C$ due to the long distance Coulomb interaction should be taken into account. For unpolarized scattering, ${\delta }_C$ is commonly considered as well established. Here, we evaluate the Coulomb phase shifts for the forward elastic proton-proton single spin-flip electromagnetic and hadronic amplitudes. Only a small discrepancy between the spin-flip and non-flip phases was found which can be neglected in the high energy forward elastic $pp$ studies involving transverse spin. Nonetheless, the effective alteration of the hadronic spin-flip amplitude by the long distance electromagnetic corrections can be essential for interpretation of the experimental results.

Comments: 5 pages, 1 figure