1. Istituto di Fisica dell'' Università, Pisa, Italy;2. INFN, Sezione di Pisa, Italy
Abstract:
New results on a high statistics measurement of pion-nucleon charge exchange scattering at 40 GeV/c, extending in momentum transfer up to ?t = 1.8 (GeV/c)2, are reported and compared with an optical impact parameter model, together with previous data for the reaction π?p → ηn at the same energy. The imaginary part of the pole trajectory b0(s) is determined from the slope of the tangent to the maxima of . The linear increase of Im b0(s) with log s, which has been observed at low energies, continues up to 40 GeV/c.