论文标题

$ {\ cal o}(α_SV^2)$校正向量Quarkonia

${\cal O}(α_sv^2)$ corrections to hadronic decay of vector quarkonia

论文作者

Sang, Wen-Long, Feng, Feng, Jia, Yu

论文摘要

在非派别QCD(NRQCD)分解框架中,我们计算了$ {\ Mathcal O}(α_sv^2)$校正向量Quarkonia的HADRONIC衰减率,以$ j/ψ$和$购来示例。将重归其化和NRQCD分数量表都设置为$ M_Q $,我们获得$γ(j/ψ\ to {\ rm lh})= 0.0716 \ frac {α_s^3} {m_c^2} \ langle \ Mathcal {O} _1({}^3S_1)\ rangle_ {J/ψ} [1-1.19α_s+( - 5.32+3.03α_s)\ langle v^2 \ rangle_ \ rangle_ {J/ψ}] 0.0716 \ frac {α_s^3} {m_b^2} \ langle \ mathcal {o} _1({}^3S_1)\ rangle_管理[1-1.56α_S+(-5.32+4.611α_S)\4.61α_S)\ langle v^2 \ rang_]我们以图表为基础确认$ \ Mathcal {O}(α_s)$校正的先前计算,其精度显着提高。对于$ J/ψ$ HADRONIC衰变,我们发现$ {\ Mathcal O}(α_SV^2)$校正是中等且积极的,但是无法抵消巨大的负面校正。另一方面,$ {\ mathcal o}(α_sv^2)$ chorkions $υ(ns)$的效果对$ \ narccal {o}(v^2)$ nrqccd matrix元素很敏感。通过适当选择NRQCD矩阵元素,我们对衰减率的理论预测可能与$υ(1s,2s)\ to {\ rm LH} $的实验数据一致。作为副产品,我们还介绍了$ j/ψ(υ)\3γ$精确度为$ \ MATHCAL {O}(α_Sv^2)$的分支比例的理论预测。

Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the ${\mathcal O}(α_s v^2)$ corrections to the hadronic decay rate of vector quarkonia, exemplified by $J/ψ$ and $Υ$. Setting both the renormalization and NRQCD factorization scales to be $m_Q$, we obtain $Γ(J/ψ\to {\rm LH})= 0.0716\frac{α_s^3}{m_c^2} \langle \mathcal{O}_1({}^3S_1)\rangle_{J/ψ} [1-1.19α_s+(-5.32+3.03α_s)\langle v^2\rangle_{J/ψ}]$ and $Γ(Υ\to {\rm LH})= 0.0716\frac{α_s^3}{m_b^2}\langle\mathcal{O}_1({}^3S_1)\rangle_Υ[1-1.56α_s+(-5.32+4.61α_s)\langle v^2\rangle_Υ]$. We confirm the previous calculation of $\mathcal{O}(α_s)$ corrections on a diagram-by-diagram basis, with the accuracy significantly improved. For $J/ψ$ hadronic decay, we find that the ${\mathcal O}(α_sv^2)$ corrections are moderate and positive, nevertheless unable to counterbalance the huge negative corrections. On the other hand, the effect of ${\mathcal O}(α_sv^2)$ corrections for $Υ(nS)$ is sensitive to the $\mathcal{O}(v^2)$ NRQCD matrix elements. With the appropriate choice of the NRQCD matrix elements, our theoretical predictions for the decay rates may be consistent with the experimental data for $Υ(1S,2S)\to {\rm LH}$. As a byproduct, we also present the theoretical predictions for the branching ratio of $J/ψ(Υ)\to 3γ$ accurate up to $\mathcal{O}(α_s v^2)$.

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