Observations of a Backward Peak in π-p→pρ- at 8 and 16 GeV/c

We report differential cross sections for ρ- production near 180°in the reaction π-p→pρ- at 8 and 16 GeV/c. These cross sections, which cover a range of |u|<~0.6 (GeV/c)2, are well represented by the formula dσdu=Aexp(Bu) and are comparable in magnitude to backward π-p elastic cross sections. Results are compared to Regge model calculations. © 1969 The American Physical Society.