论文标题
在HAL QCD方法中对Tetraquark州$ T_ {BB} $的晶格研究
Lattice study on a tetraquark state $T_{bb}$ in the HAL QCD method
论文作者
论文摘要
我们调查了一个双重底部的Tetraquark State $ t_ {bb} $ $（bb \ bar {u} \ bar {d}）$，带量子数$ i（j^p）= 0（j^p）= 0（1^+）$ in $（2+1）$（2+1）$ - 风味lattice lattice lattice lattice QCD。使用$ b $ quarks的非相关性QCD（NRQCD）夸克动作，我们在$ \ bar {b} \ bar {b}^*$和$ \ bar {b}^*\ bar {b}^*\ bar {b}^*\ bar {b}^$ in hal qcd ot $ a \ a \ a \ ain t $ a \ aint of a \ bar {b}^*$ a \ ain t $ a \ air中提取了耦合的通道电位。 64 $晶格。潜在的预测，$ \ bar {b} \ bar {b}^*$ threshold的存在$ t_ {bb} $的存在。在物理pion质量$m_π\大约140 $ {meV}中，从$m_π\ \ \ 410，\，570，\，700 $ {meV}中，具有统计错误的绑定能量由$ e _ {\ rm binding}^{\ rm rm（c）c = 83（c = 83）给出了其统计错误由于虚拟$ \ bar {b}^*\ bar {b}^*$状态由耦合的通道电位包含，而我们获得$ e _ {\ rm binding}^{\ rm（single）} = 155（17）$ MEV仅来自单个$ \ bar {b} b} {b}的潜在潜力。此差异表明，虚拟$ \ bar {b}^* \ bar {b}^* $状态的效果与$ t_ {bb} $的绑定能量相当。添加$ \ pm 20 $ meV作为由$ b $ quarks的NRQCD近似引起的经验系统错误，我们对$ t_ {bb} $ binding Energy的估计变为$ 83（10）（20）$ MEV。
We investigate a doubly-bottomed tetraquark state $T_{bb}$ $(bb \bar{u}\bar{d})$ with quantum number $I(J^P)=0(1^+)$ in $(2+1)$-flavor lattice QCD. Using the Non-Relativistic QCD (NRQCD) quark action for $b$ quarks, we have extracted the coupled channel potential between $\bar{B}\bar{B}^*$ and $\bar{B}^* \bar{B}^*$ in the HAL QCD method at $a \approx 0.09$ {fm} on $32^3\times 64$ lattices. The potential predicts an existence of a bound $T_{bb}$ below the $\bar{B}\bar{B}^*$ threshold. At the physical pion mass $m_π\approx140$ {MeV} extrapolated from $m_π\approx 410,\, 570,\, 700$ {MeV}, a binding energy with its statistical error is given by $E_{\rm binding}^{\rm (coupled)} = 83(10)$ MeV from a coupled channel analysis where effects due to virtual $\bar{B}^* \bar{B}^*$ states are included through the coupled channel potential, while we obtain $E_{\rm binding}^{\rm (single)} = 155(17)$ MeV only from a potential for a single $\bar{B}\bar{B}^*$ channel. This difference indicates that the effect from virtual $\bar{B}^* \bar{B}^*$ states is sizable to the binding energy of $T_{bb}$. Adding $\pm 20$ MeV as empirical systematic error caused by the NRQCD approximation for $b$ quarks, our estimate of the $T_{bb}$ binding energy becomes $83(10)(20)$ MeV.
