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arXiv 2301.07698hep-phhep-ex
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夸克-强子对偶在起作用:底重重子的寿命

Quark-hadron duality at work: lifetimes of bottom baryons

James Gratrex, Alexander Lenz, Blaženka Melić, Ivan Nišandžić, Maria Laura Piscopo, Aleksey V. Rusov

AI总结:

该研究在HQE框架下预测底重重子寿命,首次纳入Darwin项并更新六维四夸克算符矩阵元,结果与实验吻合,支持QHD。

摘要:

在20世纪90年代,寿命比$τ(Λ_b)/τ(B_d)$的实验值非常低,引发了人们对重夸克展开(HQE)适用性的大量怀疑;该方法基于对单举总衰变率采用夸克-强子对偶(QHD)的假设。然而,这些低值后来被证明完全是实验问题所致,目前HFLAV平均值为$τ(Λ_b)/τ(B_d)=0.969(6)$。在本工作中,我们在HQE框架内给出了对$b$重子寿命的标准模型预测。特别地,我们首次纳入了Darwin项的贡献,并更新了对六维四夸克算符矩阵元的估计。在实验和理论不确定性范围内,我们发现数据与HQE预测高度一致,因此没有任何QHD受到明显破坏的迹象。我们的数值结果可概括为以下比值:$τ(Λ_b)/τ(B_d)=0.955(14)$、$τ(Ω_b^-)/τ(B_d)=1.081(42)$以及$τ(Ξ_b^0)/τ(Ξ_b^-)=0.929(28)$。

英文摘要:

In the 1990s, very low experimental values for the lifetime ratio $τ(Λ_b)/τ(B_d)$ triggered a considerable amount of doubt in the applicability of the heavy quark expansion (HQE), which is based on the assumption of quark-hadron duality (QHD) for inclusive total decay rates. However, these low values turned out to be the result of purely experimental problems, and the current HFLAV average reads $τ(Λ_b)/τ(B_d) = 0.969(6)$. In this work, we present the Standard Model predictions for the $b$-baryon lifetimes within the framework of the HQE. In particular, we include for the first time the contribution of the Darwin term and we update the estimates for the matrix elements of the dimension-six four-quark operators. Within experimental and theoretical uncertainties, we find excellent agreement between the data and the HQE predictions, and thus no indication for any visible violation of QHD. Our numerical results can be summarised by the ratios $τ(Λ_b)/τ(B_d) = 0.955(14)$, $τ(Ω_b^-)/τ(B_d) = 1.081(42)$, and $τ(Ξ_b^0)/τ(Ξ_b^-) = 0.929(28)$.

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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