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arXiv 0908.4300hep-ph
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利用BABAR新的e+e- -> pi+pi-截面数据重新评价强子对μ子磁异常的贡献

Reevaluation of the hadronic contribution to the muon magnetic anomaly using new e+e- -> pi+pi- cross section data from BABAR

M. Davier, A. Hoecker, B. Malaescu, C. Z. Yuan, Z. Zhang

摘要:

利用最近发表的高精度的BABAR实验的π + π-截面数据,我们重新计算了μ子反常磁矩的最低阶强子贡献a_mu[had,LO].我们采用新开发的软件,具有改进的数据插值和平均,更准确的误差传播和系统验证。有了新的数据,之间的差异的e+e-和τ为基础的结果占主导地位的双π介子模式减少从以前的2.4西格玛到1.5西格玛的色散积分,虽然显着的局部差异的光谱持续。对于基于e+e的估计,我们得到amu[had,LO] =(695.5 +- 4.1)10^-10,其中误差考虑了所有源。a_mu的完整标准模型预测值与实验值相差3.2 sigma。

英文摘要:

Using recently published, high-precision pi+pi- cross section data by the BABAR experiment from the analysis of e+e- events with high-energy photon radiation in the initial state, we reevaluate the lowest order hadronic contribution a_mu[had,LO] to the anomalous magnetic moment of the muon. We employ newly developed software featuring improved data interpolation and averaging, more accurate error propagation and systematic validation. With the new data, the discrepancy between the e+e- and tau-based results for the dominant two-pion mode reduces from previously 2.4 sigma to 1.5 sigma in the dispersion integral, though significant local discrepancies in the spectra persist. We obtain for the e+e- based evaluation amu[had,LO] = (695.5 +- 4.1) 10^-10, where the error accounts for all sources. The full Standard Model prediction of a_mu differs from the experimental value by 3.2 sigma.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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