τ的轻子衰变研究
On the leptonic decays of the $τ$
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中文总结 AI 辅助
针对轻子τ衰变τ→ℓν_τν̄_ℓ，研究人员在标准模型框架下，结合高阶修正计算衰变宽度，推导次次领头阶结果并评述相关衰变对方案转换的关键作用。
中文摘要 AI 辅助
鉴于未来轻子τ衰变τ→ℓν_τν̄_ℓ（ℓ=e,μ）分支比可能的改进，推导超出次领头阶的标准模型对应预测恰逢其时。我们利用μ子衰变中已在overline{MS}方案下研究到三圈阶的高阶修正，给出完全 inclusive 衰变宽度的基准值。为获得完整的次次领头阶结果，我们在壳方案中对两圈系数进行数值计算，包括强子效应的评估，并将轻子结果与已知的overline{MS}系数（在可用处）进行比较。我们的最终结果以overline{MS}方案呈现，以便也能包含三圈贡献的估计。此外，我们评述了辐射衰变和稀有衰变，这些衰变的考虑对overline{MS}与壳方案结果之间的转换至关重要。
英文摘要
In view of potential future improvements in the branching fractions of leptonic $τ$ decays $τ\to\ellν_τ\barν_\ell$, $\ell=e,μ$, it is timely to derive the corresponding Standard-Model predictions beyond next-to-leading order. We provide such benchmark values for the fully inclusive decay widths, profiting from higher-order corrections that have been studied in the $\overline{\text{MS}}$ scheme up to three-loop order in the case of muon decay. To obtain complete next-to-next-to-leading-order results, we perform a numerical calculation of the two-loop coefficients in the on-shell scheme, including an evaluation of the hadronic effects, and compare the leptonic results to the known $\overline{\text{MS}}$ coefficients where available. Our final results are presented in the $\overline{\text{MS}}$ scheme, to be able to also include an estimate of the three-loop contribution. In addition, we comment on radiative and rare decays, whose consideration is critical for the conversion between $\overline{\text{MS}}$ and on-shell results.
发表机构
- University of Bern（伯尔尼大学）
- INFN, Sezione di Pisa and Scuola Normale Superiore（意大利国家核物理研究所比萨分部与比萨高等师范学院）
- University of Liverpool（利物浦大学）
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