地球中微子能谱计算及初步高阶修正

地球中微子是目前实验测量放射性生热及探索地球内部结构最好的媒介之一，而能谱是其通量预测及本底分析的前提条件。通过计算²³⁸U和²³²Th衰变链中分别对应的113和83个β衰变谱并归一化叠加，得到了这两种同位素的地球中微子能谱，较目前常用的能谱使用了更多的衰变道信息。为提高能谱的精度，对能谱加入了形状、辐射、弱磁共4项高阶修正，修正量最大达8.5%，经过修正的能谱可用于地球中微子的精确预测及分析。

Calculation and Preliminary High-order Correction of Geo-neutrino Energy Spectrum

Geo-neutrino is one of the best messengers for experimentally measuring radiogenic power and exploring the Earth’s interior. Energy spectrum is the prerequisite for predicting the geo-neutrino flux and analyzing backgrounds. By calculating and summing up the normalized β decay spectra of 113 transitions in ²³⁸U chain and 83 transitions in ²³²Th chain, the energy spectra for these two isotopes were obtained. The spectra were calculated with more beta transitions compared with the commonly used spectra at present. To improve the accuracy, four high-order corrections including the finite size correction, radioactive correction, and weak magnetism correction were considered. The biggest correction size reaches 8.5%. The corrected spectra can be used for accurate prediction and analysis of geo-neutrinos.