Proton-proton elastic scattering at 6.0 GeV/cwith three spins measured

Abstract

The differential elastic $p-p$ scattering cross section was measured at 6 GeV/c at the Argonne Zero Gradient Synchrotron in the range ${p_{\perp }}^2 = 0.6-1.0$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ using a 65%-polarized target and a 75%-polarized extracted beam of intensity 3 × ${10}^9$ protons/pulse. We simultaneously measured the polarization of the recoil proton with a well-calibrated carbon-target polarimeter. All three polarizations were measured perpendicular to the horizontal scattering plane. Our results indicate that $P$ and $T$ invariance are both obeyed to good precision even at large ${p_{\perp }}^2$. Parity invariance implies that the eight single-flip transversity cross sections are zero, so our data give the relative magnitudes of the eight remaining pure spin cross sections where all spins are measured. We find that the double-flip transversity cross sections are nonzero.