论文标题
MUON的异常磁矩：晶格QCD计算的状态
The anomalous magnetic moment of the muon: status of Lattice QCD calculations
论文作者
论文摘要
近年来，MUON的异常磁矩在晶格QCD社区中引发了很多活动，因为在现象学估计和Brookhaven测量之间观察到了持续的张力约为3.5 〜σ $。当前的最佳现象学估计值具有与实验性估计值相当的不确定性，并且误差完全由Hadronic效应支配：领先的HADRONIC真空极化（HVP）贡献和Hadronic Light-Light（HLBL）散射贡献。两者都可以通过晶格模拟访问，并且鉴于Fermilab和J-Parc即将进行的实验，需要将误差减少到因子4中，这些实验在未来几年内预期的结果应将实验精度降低到0.14〜$ ppm。在本文中，我回顾了从HVP开始的这些数量晶格计算的状态。现在，此贡献已达到次级精度，需要仔细了解系统错误的所有来源。 HLBL的贡献要小得多，但仍会对错误产生重大贡献。这项贡献的计算更具挑战性，但是在过去几年中，晶格已经取得了迅速的进步。
In recent years, the anomalous magnetic moment of the muon has triggered a lot of activity in the lattice QCD community because a persistent tension of about $3.5~σ$ is observed between the phenomenological estimate and the Brookhaven measurement. The current best phenomenological estimate has an uncertainty comparable to the experimental one and the error is completely dominated by hadronic effects: the leading order hadronic vacuum polarization (HVP) contribution and the hadronic light-by-light (HLbL) scattering contribution. Both are accessible via lattice simulations and a reduction of the error by a factor 4 is required in view of the forthcoming experiments at Fermilab and J-PARC whose results, expected in the next few years, should reduce the experimental precision down to the level of $0.14~$ppm. In this article, I review the status of lattice calculations of those quantities, starting with the HVP. This contribution has now reached sub-percent precision and requires a careful understanding of all sources of systematic errors. The HLbL contribution, that is much smaller, still contributes significantly to the error. This contribution is more challenging to compute, but rapid progress has been made on the lattice in the last few years.
