HEAVY NEUTRINOS AND THE BETA SPECTRA OF S-35, F-18, AND NE-19
HEAVY NEUTRINOS AND THE BETA SPECTRA OF S-35, F-18, AND NE-19
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重中微子和 S-35、F-18 和 NE-19 的 β 光谱
DOI：
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发表时间：
1983
期刊：
影响因子：
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通讯作者：
D. Millener
中科院分区：
文献类型：
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作者：
F. Calaprice;D. Millener
我们计算了/sup 18/F、/sup 19/Ne和/sup 35/S β衰变的弱磁性和其它高阶矩阵元。矩阵元素来自sd壳模型波函数来自一个和两个身体的有效相互作用的钟和Wildenthal。β谱的形状计算假设零质量中微子，并允许高阶矩阵元素。计算结果表明，精确测量这些谱对于寻找中微子质量在20 keV ~ 2 MeV范围内强度大于10/sup-3/量级的重中微子是有用的。虽然其他观测可能会排除大质量中微子混合的这些参数，但光谱的测量将提供最直接和最不确定的限制。对于/sup 18/F和/sup 19/Ne的允许衰变，弱磁性形状因子似乎是占主导地位的高阶效应。在这两种情况下，模拟M1矩阵元素是已知的实验，因此弱磁项是通过守恒矢量流理论确定的。人们也可以把这些光谱的测量看作是守恒矢量流预测的检验。
We evaluate the weak magnetism and other higher order matrix elements for the beta decays of /sup 18/F, /sup 19/Ne, and /sup 35/S. The matrix elements were obtained from sd shell-model wave functions derived from the one- and two-body effective interactions of Chung and Wildenthal. The shapes of the beta spectra are calculated assuming zero-mass neutrinos and allowing for the higher order matrix elements. The calculations suggest that precise measurements of these spectra would be useful to search for heavy neutrinos with intensities of the order of >10/sup -3/ over the neutrino mass range from 20 keV to 2 MeV. While other observations may rule out such parameters for mixing of massive neutrinos, the measurements of spectra would provide the most direct and least uncertain limits. For the allowed decays of /sup 18/F and /sup 19/Ne the weak magnetism form factor appears to be the dominant higher order effect. The analog M1 matrix elements are known experimentally in both cases and thus the weak magnetism terms are determined through the conserved vector current theory. One might alternatively regard measurements of these spectra as tests of the conserved vector current predictions.