强子W玻色子衰变宽度未计算的N⁵LO量子色动力学贡献的基于概率的估计
Probability-based Estimates of the Uncalculated N$^5$LO QCD Contribution to the Hadronic $W$-Boson Decay Width
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中文总结 AI 辅助
本研究针对N⁵LO量子色动力学修正无法精确计算的问题，采用共形性最大原理改进微扰级数，结合贝叶斯分析估计N⁵LO贡献，得到与实验数据一致的W玻色子强子衰变分支比。
中文摘要 AI 辅助
目前，W玻色子强子衰变宽度的微扰量子色动力学修正已被知晓到next-to-next-to-next-to-next-to-leading order（N⁴LO，即次四次领头阶），而精确的N⁵LO修正因计算复杂度极高仍无法获得。本研究采用贝叶斯分析（BA）来估计N⁵LO贡献。在估计前，运用共形性最大原理（PMC）提升初始依赖标度的微扰级数的精度。通过递归应用重整化群方程，将非共形项吸收到强耦合跑动中，得到与方案无关、标度不变且收敛性更好的微扰级数。该PMC程序确定了有效耦合α_s(Q_*)，在次次领头对数精度下，PMC标度固定为Q_* = 100.102 GeV。基于改进且更精确的级数，95.5%的BA可信区间给出的不确定性为Δδ_QCD|_{PMC, BA}^{N⁵LO} = ±1.0×10⁻⁵。所得的强子分支比为B(W→强子)|_{PMC} = (65.84±1.54)%，该结果在合理误差范围内与实验数据一致。
英文摘要
The perturbative QCD corrections to the hadronic decay width of the $W$ boson are currently known up to next-to-next-to-next-to-next-to-leading order ($\mathrm{N^4LO}$), whereas the exact $\mathrm{N^5LO}$ correction remains unavailable owing to its formidable computational complexity. In this work, we estimate the $\mathrm{N^5LO}$ contributions by adopting Bayesian analysis (BA). Before performing the estimation, the Principle of Maximum Conformality (PMC) is employed to improve the precision of the initial scale-dependent perturbative series. Through recursive application of the renormalization group equation, non-conformal terms are absorbed into the strong running coupling, yielding a scheme-independent, scale-invariant perturbative series with improved convergence. The PMC procedure determines an effective coupling $α_s(Q_*)$, with the PMC scale fixed as $Q_* = 100.102~\mathrm{GeV}$ at next-to-next-to-leading logarithmic accuracy. Based on the improved and more precise series, the $95.5\%$ BA credible interval yields an uncertainty of $Δδ_\mathrm{QCD}|_{\mathrm{PMC, BA}}^{\mathrm{N^5LO}} = \pm 1.0\times 10^{-5}$. The resulting hadronic branching ratio is $\mathcal{B}(W\to \text{hadrons})|_\mathrm{PMC} = (65.84\pm 1.54)\%$, which is consistent with experimental data within reasonable errors.
发表机构
- Chongqing University（重庆大学）
- Chinese Academy of Sciences（中国科学院）
机构由 AI 辅助整理，请以论文原文为准。
