Measurement ofΔσLin proton-proton scattering between 300 and 800 MeV

We have measured the difference between proton-proton total cross sections for parallel and antiparallel longitudinal spin states [$\Delta {\sigma }_L={\sigma }^{\mathrm{tot}}(\rightleftarrows )-{\sigma }^{\mathrm{tot}}(\rightleftarrows )$] at 13 incident energies between 300 and 800 MeV, which cover the region of possible ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}F_3^{}{}_{}{}^{}$ diproton resonances. The present experiment has strongly confirmed the structure previously observed at the Argonne Zero Gradient Synchrotron. No additional narrow structure has been found.