Determination of Vacuum Regge Poles and Cuts

Abstract

The sum of the ${\pi }^{+}p$ and ${\pi }^{-}p$ forward elastic scattering amplitudes at high energies is studied from the standpoint of complex angular momentum. Experimental total cross sections and real parts, as well as the Igi sum rule, are used. It is found that excellent fits can be obtained using either two Regge poles (the $P$ and the $P^{\prime }$) or a pole and a cut (the $P$ and the $PP$). Two-pole fits indicate that the Pomeranchukon intercept lies in the interval $0.92\le {\alpha }_P\mathrm{}\left(0\right)\mathrm{}\le 1.00$. Prospects for improving these bounds with data at higher energies are investigated.