论文标题
共振是$ x_0（2900）$地基州还是径向兴奋的标量tetraquark $ [ud] [\ overline {c} \ overline {s}] $？
Is the resonance $X_0(2900)$ a ground-state or radially excited scalar tetraquark $[ud][\overline{c}\overline{s}]$?
论文作者
论文摘要
我们调查了地面状态和第一次径向激动的四夸克中的属性$ x_0 $和$ x_0^{\ prime} $，带有diquark-antidiquark结构$ [ud] [\ overline {c} \ overline {c} \ overline {s} {s} {s}] $ $ j^{\ j^{\ mathrm $ j^{\ mathrm {p} $ {我们的目的是揭示是否可以通过LHCB协作最近发现的共振$ x_0（2900）$来识别这些状态之一。我们将$ x_0 $和$ x_0^{\ prime} $建模为由轴向矢量或标量diquark和Andidiquark对组成的四夸克。它们的光谱参数是通过采用QCD两点总规则方法来计算的，并将其包括在分析真空中，直至尺寸$ 15 $。对于$ x_0^{（\ prime）} $的轴向轴结构，我们发现衰减的部分宽度$ x_0^{（\ prime）} \ to d^{ - } k^{+} $ and $ x_0^{（\ prime）} $ x_0^{（\ prime）} $。为此，我们在轻锥总规则方法的框架中计算了顶点$ x_0^{（\ prime）} dk $的强耦合。我们还使用所需的软膜近似技术方法来分析Tetraquark-Meson-Meson顶点。获得的结果$ m =（2545 \ pm 160） $ m _ {\ mathrm {s}}^{\ prime} =（3325 \ pm 85） 29）〜\ mathrm {mev} $和$γ_{0}^{\ prime} =（110 \ pm 25）〜\ mathrm {mev} $允许我们不将它们解释为共振$ x_0（2900）$。同时，这些预测提供了有关地面和径向激发的diquark-antidiquark结构$ x_0 $和$ x_0^{\ prime} $的重要信息，这应该是未来实验和理论研究的对象。
We investigate properties of the ground-state and first radially excited four-quark mesons $X_0$ and $X_0^{\prime}$ with a diquark-antidiquark structure $[ud][\overline{c}\overline{s}]$ and spin-parities $J^{\mathrm{P} }=0^{+}$. Our aim is to reveal whether or not one of these states can be identified with the resonance $X_0(2900)$, recently discovered by the LHCb collaboration. We model $X_0$ and $X_0^{\prime}$ as tetraquarks composed of either axial-vector or scalar diquark and antidiquark pairs. Their spectroscopic parameters are computed by employing the QCD two-point sum rule method and including into analysis vacuum condensates up to dimension $ 15$. For an axial-axial structure of $X_0^{(\prime)}$, we find partial widths of the decays $X_0^{(\prime)} \to D^{-}K^{+}$ and $X_0^{(\prime)} \to D^{0}K^{0}$, and estimate full widths of the states $X_0^{(\prime)}$. To this end, we calculate the strong couplings at the vertices $ X_0^{(\prime)}DK $ in the framework of the light-cone sum rule method. We use also technical approaches of the soft-meson approximation necessary to analyze tetraquark-meson-meson vertices. Obtained results $m=(2545 \pm 160)~ \mathrm{MeV}$ and $m^{\prime}=(3320 \pm 120)~\mathrm{MeV}$ [$m_{\mathrm{S} }=(2663 \pm 110)~\mathrm{MeV}$ and $m_{\mathrm{S}}^{\prime}=(3325 \pm 85)~ \mathrm{MeV}$ for a scalar-scalar current] for the masses of the particles $ X_0$ and $X_0^{\prime}$, as well as estimates for their full widths $ Γ_{0}=(140 \pm 29)~\mathrm{MeV}$ and $Γ_{0}^{\prime}=(110 \pm 25)~ \mathrm{MeV}$ allow us to interpret none of them as the resonance $X_0(2900)$ . At the same time, these predictions provide important information about ground-state and radially excited diquark-antidiquark structures $X_0$ and $ X_0^{\prime}$, which should be objects of future experimental and theoretical studies.
