论文标题
计算$π^0 \ rightarrow e^+ e^ - $衰减振幅的两光子贡献
Calculating the Two-photon Contribution to $π^0 \rightarrow e^+ e^-$ Decay Amplitude
论文作者
论文摘要
我们开发了一种新方法，使我们能够在晶格QCD计算中处理两光子中间状态。我们将此方法应用于$π^0 \ rightarrow e^+ e^ - $衰减幅度的第一原理计算。计算振幅的真实部分和虚构部分。假想部分与光学定理的预测相提并论，以证明该方法的有效性。我们对衰减幅度的实际部分的结果是$ 19.68（52）（1.10）\ \ text {ev} $，其中第一个错误是统计的，第二个错误是系统的。
We develop a new method that allows us to deal with two-photon intermediate states in a lattice QCD calculation. We apply this method to perform a first-principles calculation of the $π^0 \rightarrow e^+ e^-$ decay amplitude. Both the real and imaginary parts of amplitude are calculated. The imaginary part is compared with the prediction of optical theorem to demonstrate the effectiveness of this method. Our result for the real part of decay amplitude is $19.68(52)(1.10) \ \text{eV}$, where the first error is statistical and the second is systematic.
