Backward elastic scattering and rho production in π-p collisions at 10 GeV/c

The reactions π-p → pπ- and π-p → pp- (p- → π-π0) at 10 GeV/c with the proton in the forward direction in the c.m.s. are discussed on the basis of 953 elastic scattering events and 2240 events of the reaction π-p → pπ-π0. The total backward cross sections are 0.52 +- 0.10 and 1.52 +- 0.28 μb, respectively. In both cases the production mechanism is compatible with the dominance of the baryonic Δsub(delta) Regge trajectory exchange. The p- decay angular distributions are studied in the u-channel helicity frame and the spin density matrix elements are presented as functions of u. (orig.)