Measurement ofΔσLandCLL=(L,L;0,0)in proton-proton scattering between 300 and 800 MeV

Measurements are reported of the difference $\Delta {\sigma }_L$ between proton-proton total cross sections for parallel and antiparallel spin states and of the parameter $C_{\mathrm{LL}}$ for proton-proton elastic scattering near 90°, for thirteen energies between 300 and 800 MeV. The $\Delta {\sigma }_L$ results agree well with previous ANL ZGS and SIN data, but disagree with recent results from TRIUMF. Attempts to understand the cause of the discrepancy have been unsuccessful, but possible sources are discussed. The $\Delta {\sigma }_L$ and $C_{\mathrm{LL}}$ results have been used with other experimental data to extract quantities which depend only on spin-singlet, coupled spin-triplet, and spin-triplet partial waves. Structure is found in these quantities, which appears to be associated with the resonantlike ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$ and ${}_{}{}^3{}_{}{}^{}F_3^{}{}_{}{}^{}$ partial waves. Additional similar structure is also found, which may be due either to the ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$ partial wave or the (${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}$,${}_{}{}^3{}_{}{}^{}F_2^{}{}_{}{}^{}$) partial-wave pair.