Zeros, Dips and Signs in pp and p$\bar{\mathbf{p}}$ Elastic Amplitudes

Abstract

The dips observed in the differential cross sections of elastic pp and p$\bar{\mathrm{p}}$ scattering are studied in terms of the locations of the zeros of the real and imaginary parts of the amplitude and of the sign of real part at large $|t|$. It is confirmed that the differences in shapes of the dips in the pp and p$\bar{\mathrm{p}}$ systems are determined by a change of sign of the real tail, which seems to be determined by perturbative QCD contributions.

Comments: LaTex, 9 pages, 5 figures. Submitted to Phys. Rev. D