Modeling neutrino-induced charged pion production on water at T2K kinematics

Abstract

Background: Pion production is a significant component of the signal in accelerator-based neutrino experiments. Over the last years, the MiniBooNE, T2K and MINERvA collaborations have reported a substantial amount of data on (anti)neutrino-induced pion production on the nucleus. However, a comprehensive and consistent description of the whole data set is still missing.Purpose: We aim at improving the current understanding of neutrino-induced pion production on the nucleus. To this end, the comparison of experimental data with theoretical predictions, preferably based on microscopic models, is essential to disentangle the different reaction mechanisms involved in the process.Method: To describe single-pion production (SPP) we use a hybrid model that combines a low-and a highenergy approach. The low-energy model (LEM) contains resonances and background terms. At high invariant masses, a high-energy model based on a Regge approach is employed. The model is implemented in the nucleus using the relativistic plane wave impulse approximation (RPWIA). Results:We present a comparison of the hybrid-RPWIA and LEM with the recent neutrino-induced charged current 1π + production cross section on water reported by T2K. In order to judge the impact of final-state interactions (FSI) we confront our results with those of the NuWro Monte Carlo generator. Conclusions:The hybrid-RPWIA model and NuWro compare favorably to the data, albeit that FSI are not included in the former. The need of a high-energy model at T2K kinematics is made clear. These results complement our previous work [Phys. Rev. D 97, 013004 (2018)] where we compared the models to the MINERvA and MiniBooNE 1π + data. The hybrid-RPWIA model tends to overpredict both the T2K and MINERvA data in kinematic regions where the largest suppression due to FSI is expected, and agrees remarkably well with the data in other kinematic regions. On the contrary, the MiniBooNE data is underpredicted over the whole kinematic range.

Ab Initio Study of (νℓ,ℓ−) and (ν¯<

“…Many of the above models have achieved remarkable success and much improved agreement with experimental data, compared to simple RFG calculations. A number of them are applicable to energies higher than those corresponding to the quasielastic peak, and account for pion production and resonance excitations [32][33][34][35][36]. Others are suitable to model the low-energy region of the response functions characterized by peaks corresponding to collective modes and transitions to discrete excited states [37,38].…”

Event Generators for High-Energy Physics Experiments

“…In this scheme, any simulated event is a two-step process with an initial (hard) neutrino scattering off a bound nucleon (or a pair of nucleons) followed by final-state interactions (FSI) of knocked-out nucleons, hyperons and produced pions. Together with various supplemental nuclear effects, this simple picture can reproduce many experimental results for both inclusive [1060][1061][1062] and exclusive [969,1063,1064] cross sections measurements.…”

A New Generation of Neutrino Cross Section Experiments: Challenges and Opportunities

“…[140][141][142] and Refs. [143,144] reproduce well the shape and strength of the MINERvA and T2K data but underpredict the MiniBooNE ones. This is the so called "pion puzzle".…”