Energy dependence of spin-spin effects in p-p elastic scattering at 90/sup 0//sub c. m. /

The energy dependence of the spin-parallel and spin-antiparallel cross sections for p/sub arrow-up/+p/sub arrow-up/..-->..p+p at 90/sup 0//sub c.m./ was measured for beam momenta between 6 and 12.75 GeV/c. The ratio (dsigma/dt)/sub parallel/:(dsigma/dt)/sub antiparallel/ at 90/sup 0/ is about 1.2 up to 8 GeV/c and then increases rapidly to a value of almost 4 near 11 GeV/c. Our data indicate that this ratio may depend only on the variable P/sub perpendicular/ /sup 2/, and suggests that the ratio may reach a limiting value of about 4 for large P/sub perpendicular/ /sup 2/.