Pureρ+ρ′Regge-pole analysis for forwardπ−p→π0nscattering from 20 to 200 GeV/c

Abstract

New data for the forward differential cross section ${(\frac{d\ensuremath{\sigma}}{\mathrm{dt}})}_{0}^{\mathrm{CEX}}$ and for $\ensuremath{\Delta}\ensuremath{\sigma}\ensuremath{\equiv}{\ensuremath{\sigma}}_{T}({\ensuremath{\pi}}^{\ensuremath{-}}p)\ensuremath{-}{\ensuremath{\sigma}}_{T}({\ensuremath{\pi}}^{+}p)$ at 20 to 200 GeV/c are analyzed by means of the $\ensuremath{\rho}+{\ensuremath{\rho}}^{\ensuremath{'}}$ Regge-pole exchange model with no absorptive cut. In terms of ${(\frac{d\ensuremath{\sigma}}{\mathrm{dt}})}_{0}$, $\ensuremath{\Delta}\ensuremath{\sigma}$, and $r = \frac{\mathrm{Re}{A}^{\ensuremath{'}}}{\mathrm{Im}{A}^{\ensuremath{'}}}$, the $\ensuremath{\rho}+{\ensuremath{\rho}}^{\ensuremath{'}}$ model with the $\ensuremath{\rho}$ trajectory of $0.466<{\ensuremath{\alpha}}_{\ensuremath{\rho}}(0)<0.476$ and the ${\ensuremath{\rho}}^{\ensuremath{'}}$ trajectory of $\ensuremath{-}1.9<{\ensuremath{\alpha}}_{{\ensuremath{\rho}}^{\ensuremath{'}}}(0)<\ensuremath{-}1.3$ is more promising than such a model with $\ensuremath{-}0.2<{\ensuremath{\alpha}}_{{\ensuremath{\rho}}^{\ensuremath{'}}}(0)<0$. The prediction extrapolated to 1000 GeV/c suggests that another type of term should be added to the real or imaginary part of the amplitude.