Production of ρ⁰ and f in π^-p interactions at 16 GeV/c and separation into fragmentation and central components

The production of ρ⁰(770) and f(1270) is studied in π^-p interactions at 16 GeV/c. By comparison with inclusive K^*0 production in the reaction K^-p → K^*0 + anything, and with inclusive ρ⁰ production in the reaction pp → ρ⁰ + anything, it is found that the data can be interpreted in terms of two production processes: the central production of resonances and the fragmentation of the beam particle. For the π^-p reaction, the inclusive ρ⁰ beam fragmentation cross section is 3.1 ± 0.3 mb while that for central production is 1.6 ± 0.5 mb. The ρ⁰ central production cross section is consistent with increasing with energy as ln s behaviour. The ratio of ρ⁰ to π^- inclusive cross sections (excluding the leading π^-) is ∼0.2, independent of energy. The ρ⁰ to π^- ratio increases as a function of p_T to a constant value of ∼ 1 2 above 1 GeV/c. The ρ (charged and neutral) and f decays account for (25 ± 4)% and (1.4 ± 0.3)%, respectively, of all pions produced.