Precise 8B solar neutrino spectrum for neutrino oscillation analysis

8B的太阳中微子谱是研究标准模型以外的中微子振荡的最精确的观测数据之一。在Super-Kamiokande观测到的中微子光谱的最大不确定因素之一是8B中微子发射后的光谱形状因子。在本研究中，形状因子中的弱磁性和轴向电荷矩阵元直接由β衰变的实验结果确定。形状因子中的不确定度首次基于实验不确定度进行确定。

Solar neutrino spectrum from 8B is one of the most precise observables to investigate the neutrino oscillation beyond the standard model. One of the largest uncertainties of neutrino spectrum observed at Super-Kamiokande is the spectral shape factor just after the neutrino emission from 8B. In this study, the weak magnetism and axial charge matrix elements, which are the terms in shape factor, were determined directly from experimental results of beta decay. Uncertainties in the shape factor were determined based on experimental uncertainties for the first time.