arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1912.07656hep-phhep-exhep-lat
收藏

重奇异标量介子$T_{bb;\bar{u}\bar{s}}^{-}$

Heavy exotic scalar meson $T_{bb;\bar{u}\bar{s}}^{-}$

S. S. Agaev, K. Azizi, B. Barsbay, H. Sundu

备注：
14 Pages, 5 Figures and 2 Tables
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

研究了标量四夸克态$ T_{bb;\overline{u}\overline{s}}^{-}$（以下简称$T_{b:\overline{s} }^{-} $）的光谱参数和衰变道。$T_{b:s}^{-}$的质量和耦合使用两点求和规则计算，考虑到夸克，胶子和混合真空凝聚到10维。我们对它的质量$m=(10250 \pm 270)~\mathrm{MeV}$的计算结果表明，$T_{b:\overline{s}}^{-} $对强衰变和电磁衰变是稳定的。因此，为了找到$T_{b:\overline{s}}^{-}$的宽度和平均寿命，我们探索了它的主要弱衰变产生的过渡$b \to W^{-}c$。这些通道包含半轻子衰变$T_{b:\overline{s}}^{-} \to Z_{bc;\overline{u}\overline{s}}^{0}l\overline{ ν}_{l}$和非轻子模式$T_{b:\overline{s}}^{-} \to Z_{bc;\overline{ u}\overline{s}}^{0}π^{-}(K^{-}, D^{-}, D_s^{-})$，后者在终态包含标量四夸克$Z_{bc;\overline{u}\overline{s}}^{0}$。计算弱衰变部分宽度的关键量是形状因子$G_1(q^2)$和$G_2(q^2)$：它们分别决定半轻子过程和非轻子过程部分宽度的微分速率$dΓ/dq^2$。这些形状因子是从可用于此类分析的动量转移$q^2$的相关三点和规则中提取的。通过拟合函数$F_{1(2)}(q^2)$，它们被外推以覆盖整个积分区域$m_l^{2}\leq q2\leq(m-\widetilde m)^2$，其中$\widetilde m$是$Z_{bc;\overline{u}\overline{s}}^{0}$的质量。对$T_{b:s}^{-} $的全宽$Γ_{\mathrm{full}}=(15.21\pm 2.59)\times 10^{-10}~\mathrm{ MeV}$和平均寿命$4.33_{-0.63}^{+0.89}\times 10^{-13}~\mathrm{s}$的预测对这种奇异介子的实验和理论研究是有用的。

英文摘要：

The spectroscopic parameters and decay channels of the scalar tetraquark $ T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows $T_{b:\overline{s} }^{-} $) are investigated. The mass and coupling of the $T_{b:s}^{-}$ are calculated using the two-point sum rules by taking into account quark, gluon and mixed vacuum condensates up to dimension 10. Our result for its mass $m=(10250 \pm 270)~\mathrm{MeV}$ demonstrates that $T_{b:\overline{s}}^{-} $ is stable against the strong and electromagnetic decays. Therefore to find the width and mean lifetime of the $T_{b:\overline{s}}^{-}$, we explore its dominant weak decays generated by the transition $b \to W^{-}c$. These channels embrace the semileptonic decay $T_{b:\overline{s}}^{-} \to Z_{bc;\overline{u}\overline{s}}^{0}l\overline{ ν}_{l}$ and nonleptonic modes $T_{b:\overline{s}}^{-} \to Z_{bc;\overline{ u}\overline{s}}^{0}π^{-}(K^{-}, D^{-}, D_s^{-})$, which at the final state contain the scalar tetraquark $Z_{bc;\overline{u}\overline{s}}^{0}$. Key quantities to compute partial widths of the weak decays are the form factors $G_1(q^2)$ and $G_2(q^2)$: they determine differential rate $dΓ/dq^2$ of the semileptonic and partial widths of the nonleptonic processes, respectively. These form factors are extracted from relevant three-point sum rules at momentum transfers $q^2$ accessible for such analysis. By means of the fit functions $F_{1(2)}(q^2)$ they are extrapolated to cover the whole integration region $m_l^{2}\leq q2\leq(m-\widetilde m)^2$, where $\widetilde m$ is the mass of $Z_{bc;\overline{u}\overline{s}}^{0}$. Predictions for the full width $Γ_{\mathrm{full}}=(15.21\pm 2.59)\times 10^{-10}~\mathrm{ MeV}$ and mean lifetime $4.33_{-0.63}^{+0.89}\times 10^{-13}~\mathrm{s}$ of the $T_{b:s}^{-} $ are useful for experimental and theoretical investigations of this exotic meson.

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。

↑