New measurement of the orthopositronium decay rate
New measurement of the orthopositronium decay rate
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正电子素衰变率的新测量
DOI：
10.1016/0370-2693(95)00916-9
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发表时间：
1995
影响因子：
4.4
通讯作者：
N. Shinohara
中科院分区：
文献类型：
--
作者：
S. Asai;S. Orito;N. Shinohara
正电子偶素衰变率的测量与一个全新的方法，其中拾取湮没率直接测量作为时间的函数与高分辨率锗探测器。衰变率可以在没有热化或外推的模糊性的情况下确定，这可能是以前所有实验中主要系统误差的来源。用两种不同类型的SiO2粉末进行了两次独立的测量，导致衰减速率值彼此一致。合并结果为λ0= 7.0398 ± 0.0025（stat.）± 0.0015（系统）μs−1，这与QED预测一致，与最近的三次测量结果相差2.9-4.1Φ。
The orthopositronium decay rate is measured with an entirely new method, in which the pickoff annihilation rate is directly measured as a function of time with a high-resolution germanium detector. The decay rate can be determined without the ambiguities of the thermalization nor of the extrapolation, which might have been sources of the main systematic errors in all the previous experiments. Two independent measurements are carried out with two different types of SiO2powder, resulting in decay rate values consistent with each other. The combined result is λ0= 7.0398 ± 0.0025 (stat.) ± 0.0015 (sys.) μs−1, which is consistent with the QED prediction, and differs by 2.9–4.1Φ from three recent measurements.