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

Abstract

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 νµ interactions is combined with muon kinematics to permit separation of the quasielastic and ∆(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 ∆ resonance processes are needed to describe the data. The data in this kinematic region also has an enhanced population of multi-proton 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.

Measurement of Coherent π+ Production in Low Energy Neutrino-Carbon Scattering

“…Indeed, the simulated VA distribution can be made to agree better with background data by adding VA consistent with that deposited by a proton with kinetic energy distributed uniformly between 20 and 225 MeV to 25% of background events with a neutron target. The MINERνA experiment reported a similar observation in a study of neutrino-nucleus quasielastic interactions [42,43]. The uncertainty in the vertex activity model was derived by switching this addition on and off.…”

First Measurement of Electron Neutrino Appearance in NOvA

“…The allowed variation in this effective parameter encompasses recent measurements [36][37][38][39] and is a proxy for possible multinucleon processes not included in the interaction model [40][41][42][43]. Dominant sources of uncertainty affecting the background prediction include a 5% uncertainty on both the absolute energy calibration and the interdetector energy calibration, uncertainty in the modeling of scintillator saturation by highly ionizing particles [44], and modeling of the neutrino flux.…”

Measurements of the inclusive neutrino and antineutrino charged current cross sections in MINERvA using the low- ν flux method

“…4). The agreement between the neutrino data and simulation is significantly improved with the RPA and MEC models [40]. The entire difference between the GENIE default prediction and the prediction including the RPA and MEC models is taken as the systematic uncertainty for these nuclear effects.…”