Analysis of backward πN scattering data at 3.5 GeV/c

The pion-nucleon backward scattering data at 3.5 GeV/c are fitted with two Regge-type models which were first used at 6 GeV/c: a good description of the data is obtained; however the parameters differ significantly from those at 6 GeV/c. A simultaneous fit at 3.5 and 6 GeV/c can be made with Nα and Nγ Regge amplitudes, if the non-Regge terms are fitted with separate sets of parameters at each energy.