Measurement of the differences in the total cross section for antiparallel and parallel longitudinal spins and a measurement of parity nonconservation with incident polarized protons and antiprotons at 200 GeV/<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>c</mml:mi></mml:math>

Abstract

The highest-energy measurement of $\ensuremath{\Delta}{\ensuremath{\sigma}}_{L}(\mathrm{pp})$ and the first ever measurement of $\ensuremath{\Delta}{\ensuremath{\sigma}}_{L}(\mathrm{p\ifmmode\bar\else\textasciimacron\fi{}}p)$, the differences between proton-proton and antiproton-proton total cross sections for pure longitudinal spin states, are described. Data were taken using 200-GeV/$c$ polarized beams incident on a polarized-proton target. The results are measured to be $\ensuremath{\Delta}{\ensuremath{\sigma}}_{L}(\mathrm{pp})=\ensuremath{-}42\ifmmode\pm\else\textpm\fi{}48(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}53(\mathrm{syst})$ \ensuremath{\mu}b and $\ensuremath{\Delta}{\ensuremath{\sigma}}_{L}(\mathrm{p\ifmmode\bar\else\textasciimacron\fi{}}p)=\ensuremath{-}256\ifmmode\pm\else\textpm\fi{}124(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}109(\mathrm{syst})$ \ensuremath{\mu}b. Many tests of systematic effects were investigated and are described, and a comparison to theoretical predictions is also given. Measurements of parity nonconservation at $200$ GeV/$c$ in proton scattering and the first ever of antiproton scattering have also been derived from these data. The values are consistent with zero at the ${10}^{\ensuremath{-}5}$ level.