Measurement of proton proton elastic scattering in pure initial spin states at 11.75 GeV/c

Abstract

The elastic cross section for proton proton scattering at 11.75 GeV/c was measured at the Argonne ZGS using a 50% polarized target. In the range p[perpendicular]2=0.6 --> 2.2 (GeV/c)2 we obtained precise measurements of d[sigma]/dt(ij) for the [two upwards arrow] [two down arrows], and [up and down arrow]; initial spin states perpendicular to the scattering plane. We confirmed that the asymmetry parameter, A, decreases with energy in the diffraction peak, but is approximately energy-independent at large p[perpendicular]2. We found that the spin correlation parameter cnn acquires rather dramatic structure, and at large p[perpendicular]2 seems to grow with energy.