Antineutrino-nucleon total cross section and ratio of antineutrino cross section on neutrons and protons
On a selected sample of 2171 events, observed in the big heavy liquid bubble chamber Gargamelle at CERN, the charged current total cross section for antineutrino on nucleons has been determined up to the laboratory energy Ev̄ = 8 GeV. The total cross section is found to be a linear function of the antineutrino energy expressed by σtot (Ev̄) = (0.26 +/- 0.020) × 10-38 × Ev̄ (GeV) cm2. The energy dependence of <q2>v̄ is found to be given by <q2>v̄ = (0.15 +/- 0.04)Ev̄ + (0.05 +/- 0.12) (GeV/c)2. With a simplified nuclear model the ratio of cross sections on neutrons andprotons has been estimated as a function of energy and for two different values of the scaling variable x. The results are compared with the prediction of the naive quark parton model.