Regge-Pole Model for the Secondary Maxima inπNandNNScattering and the No-Compensation Mechanism

The dip-bump structure in the low-energy ${\pi }^{\pm }p$ elastic differential cross section has been studied. We find that a zero in the helicity nonflip amplitude of the $P^{\prime }$ trajectory gives a natural explanation of this structure. At the same time we have consistently fitted the high-energy ${\pi }^{\pm }p$ total and differential cross sections, the ${\pi }^{\pm }p$ polarizations, and the ${\pi }^{-}p$ charge-exchange differential cross-section data. The helicity nonflip amplitude of the $P^{\prime }$ trajectory will vanish at ${\alpha }_{P^{\prime }}=0\mathrm{}$ if the $P^{\prime }$ trajectory chooses what we call the no-compensation mechanism. Consistent with our ${\pi }^{\pm }p$ solution, the $\mathrm{pp}$ and $\overline{p}p$ total and differential cross sections can also be well fitted. The secondary maximum in the low-energy $\overline{p}p$ differential cross section is reproduced.