Diffractive production of p-mesons and of pπ-systems by neutrinos and antineutrinos on protons

Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems in νp and anti νp charged-current interactions. In the (anti-)neutrino energy range 10 GeV<Eν<60 GeV the cross sections for diffractive ρ and diffractive ρπ production are found to be (0.64±0.14(stat.)±0.08(syst))% and (0.28±0.08(stat.)±0.04(syst.))% of the charged-current cross section. The diffractive ρπ signal is consistent with being entirely due to diffractive a1 production. However, the data cannot distinguish between diffractive a1 and diffractive nonresonant ρπ production. The experimental distributions of W, Q2, xBj and yBj for diffractive ρ and ρπ events are consistent with model predictions. (orig.)