Small-angle elastic p-p scattering at 30, 50, and 70 GeV

A thin polyethylene target was exposed to the internal proton beam of the Serpukhov accelerator at 30, 50, and 70 GeV. The wide-angle recoil protons were registered by photoemulsion stacks and the differential cross sections of the elastic p-p scattering in the range of four-momentum transfer squared 0.0025 < or = vertical-bar t vertical-bar < or = 0.12 (GeV/c)2 were measured. The ratio of the real to the imaginary part of the forward nuclear amplitude α, the slope parameter of the diffraction peak b, and the total elastic cross section sigma/sub el/ were found to be as follows : At 30 GeV, α = -0.183 +- 0.051, b = 10.61 +- 0.27 (GeV/c)-2, at 70 GeV, α = -0.104 +- 0.065, b = 11.21 +- 0.40 (GeV/c)-2, sigma/sub el/ = 7.1 +- 0.2 mb. (GeV/c)-2, sigma/sub el/ = 7.1 +- 0.2 mb. (GeV/c)-2, sigma/sub el/ = 7.1 +- 0.2 mb. (GeV/c)-2, sigma/sub el/ = 7.1 +- 0.2 mb