Speaker
Description
A precise description of single-pion production (SPP) via neutrino scattering is a critical challenge in neutrino physics, particularly for neutrino oscillation measurements and nucleon decay searches. NEUT [1] is a neutrino event generator widely utilized in neutrino experiments, such as Super-Kamiokande and T2K. While the legacy Rein-Sehgal model had long been used for SPP in NEUT, the state-of-the-art DCC model [2] has recently been implemented [3].
In this work, we report several key advancements made to address the limitations of the initial implementation. First, while the initial version assumed an isotropic pion distribution in the resonance rest frame, the updated model now calculates differential cross sections as a function of Adler angles. Second, we have newly incorporated nuclear binding energy effects; this resolves a long-standing issue where all previous SPP models in NEUT neglected these effects, consequently yielding an unphysical negative removal energy. Furthermore, since the DCC amplitudes are stored in look-up tables, evaluating systematic uncertainties is highly non-trivial. To address this challenge, we discuss the future feasibility of a reweighting method to evaluate the impact of systematic errors.
[1] Y. Hayato et al, The European Physical Journal Special Topics 230, 4469 (2021).
[2] S. X. Nakamura et al., Phys. Rev. D 92, 074024 (2015)
[3] S. Abe, Phys. Rev. D 111, 033006 (2025)