Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current ν[subscript]μ interactions is combined with muon kinematics to permit separation of the quasielastic and Δ(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and Δ resonance processes are needed to describe the data. The data in this kinematic region also have an enhanced population of multiproton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments

Identification of Nuclear Effects in Neutrino-Carbon Interactions at Low Three-Momentum Transfer

We are grateful to the authors of the RPA and 2p2h models for making the code for their calculations available for study and incorporation into this analysis. This work was supported by the Fermi National Accelerator Laboratory under U.S. Department of Energy Contract No. DE-AC02-07CH11359, which included the MINERvA construction project. Construction support was also granted by the United States National Science Foundation under Grant No. PHY-0619727 and by the University of Rochester. Support for scientists for this specific publication was granted by the United States National Science Foundation under Grant No. PHY-1306944. Support for participating scientists was provided by NSF and DOE (USA) by CAPES and CNPq (Brazil), by CoNaCyT (Mexico), by CONICYT (Chile), by CONCYTEC, DGI-PUCP and IDI/IGI-UNI (Peru), and by Latin American Center for Physics (CLAF). We thank the MINOS Collaboration for use of its near detector data. Finally, we thank the staff of Fermilab for support of the beam line, the detector, and the computing infrastructure.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte