论文标题
Belle $ y_b（10750）$共振的Tetraquark解释和生产机制
Tetraquark Interpretation and Production Mechanism of the Belle $Y_b (10750)$-Resonance
论文作者
论文摘要
最近，Belle协作已更新了该过程的横截面的分析$ e^+ e^ - \ to到υ（ns）\，π^+π^ - $（$ n = 1，\，2，2，\，3 $）在$ e^+ e^+ e^+ e^+ e^ - $中心能量范围从10.52到11.52到11.02 〜gev。 A new structure, called $Y_b (10750)$, with the mass $M (Y_b) = (10752.7 \pm 5.9^{+0.7}_{-1.1})$~MeV and the Breit-Wigner width $Γ(Y_b) = (35.5^{+17.6 +3.9}_{-11.3 -3.3})$~MeV was observed.我们将$ y_b（10750）$解释为紧凑型$ j^{pc} = 1^{ - } $状态，带有主要的tetraquark组件。大众特征态$ y_b（10750）$被视为diquark-antidiquark和$ b \ bar b $组件的线性组合，这是由于最近通过Gluonic交换的混合而来，最近显示出以大量夸克颜色的极限出现。 $ y_b $和$υ（5s）$之间的混合角可以从电子宽度估算，最近确定为$γ_{ee}（y_b）=（13.7 \ pm 1.8）$ 〜ev。该混合提供了$ y_b（10750）$生产的合理机制，从其$ b \ bar b $组件产生了高能碰撞的生产，我们在$ p p \ to y__b（10750）\ to ns（ns）\，π^+π^+π^ - $ at lHC上使用$ p p \ to y__b（10750）\ to y__b（10750）\ to y__b（10750）\ to y y_b（10750）\ the the drell-yan和迅速生产横切。出现了$ y_b（10750）\to为（1s）\，π^+π^ - $的二齿不变质量光谱的共振部分，并呈现$π^+ $ - 梅森在二臂休息框架中的相应角分布。
Recently, the Belle Collaboration has updated the analysis of the cross sections for the processes $e^+ e^- \to Υ(nS)\, π^+ π^-$ ($n = 1,\, 2,\, 3$) in the $e^+ e^-$ center-of-mass energy range from 10.52 to 11.02~GeV. A new structure, called $Y_b (10750)$, with the mass $M (Y_b) = (10752.7 \pm 5.9^{+0.7}_{-1.1})$~MeV and the Breit-Wigner width $Γ(Y_b) = (35.5^{+17.6 +3.9}_{-11.3 -3.3})$~MeV was observed. We interpret $Y_b (10750)$ as a compact $J^{PC} = 1^{--}$ state with a dominant tetraquark component. The mass eigenstate $Y_b (10750)$ is treated as a linear combination of the diquark-antidiquark and $b \bar b$ components due to the mixing via gluonic exchanges shown recently to arise in the limit of large number of quark colors. The mixing angle between $Y_b$ and $Υ(5S)$ can be estimated from the electronic width, recently determined to be $Γ_{ee} (Y_b) = (13.7 \pm 1.8)$~eV. The mixing provides a plausible mechanism for $Y_b (10750)$ production in high energy collisions from its $b \bar b$ component and we work out the Drell-Yan and prompt production cross sections for $p p \to Y_b (10750) \to Υ(nS)\, π^+ π^-$ at the LHC. The resonant part of the dipion invariant mass spectrum in $Y_b (10750) \to Υ(1S)\, π^+ π^-$ and the corresponding angular distribution of $π^+$-meson in the dipion rest frame are presented.
