Measurement of Analyzing Power for Proton-Carbon Elastic Scattering in the Coulomb-Nuclear Interference Region with a 22-GeV/c Polarized Proton Beam

TL;DR

This study measured the analyzing power for proton-carbon elastic scattering in the Coulomb-nuclear interference region using a high-energy polarized proton beam, providing insights into the spin-flip amplitude ratio.

Contribution

It presents the first measurement of the analyzing power in this specific kinematic region at 22 GeV/c, extracting the hadronic spin-flip to non-flip amplitude ratio.

Findings

Re r_5 = 0.088 ± 0.058

Im r_5 = -0.161 ± 0.226

Provides data for understanding spin effects in proton-nucleus scattering

Abstract

The analyzing power for proton-carbon elastic scattering in the coulomb-nuclear interference region of momentum transfer, $9.0\times10^{-3}<-t<4.1\times10^{-2}$ (GeV/$c)^{2}$, was measured with a 21.7 GeV/$c$ polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to non-flip amplitude, $r_5$, was obtained from the analyzing power to be $\text{Re} r_5=0.088\pm 0.058$ and $\text{Im} r_5=-0.161\pm 0.226$.