Oxford University, Department of Physics, Oxford, United Kingdom.
Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
Phys Rev Lett. 2018 Jul 13;121(2):022504. doi: 10.1103/PhysRevLett.121.022504.
Final-state kinematic imbalances are measured in mesonless production of ν_{μ}+A→μ^{-}+p+X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ^{-}-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid argon detectors where the effect of the nucleus may be even larger.
在 MINERvA 探测器中,研究了中微子与 A 核反应产生 νμ+A→μ−+p+X 的末态运动学不平衡。通过 μ−-p 横动量不平衡方向和被打中子的初始动量来探测初始和末态核效应。将微分截面与基于介质模型的现有方法的预测进行比较。这些模型在中等核内动量转移下普遍超过费米动量时,对截面的预测不足。由于为了在振荡实验中预测中微子能量分辨率,中微子相互作用模型需要正确地包含原子核的影响,因此该结果指出了在当前模型中需要额外截面强度的相空间区域,并展示了一种新技术,该技术适用于精细粒状液态氩探测器,其中原子核的影响可能更大。