论文标题
$η_1（1855）$的解释为$ k \ bar k_1（1400）+$ c.c.分子
Interpretation of the $η_1(1855)$ as a $K\bar K_1(1400)+$ c.c. molecule
论文作者
论文摘要
最近在$η_1（1855）$表示的具有$ j^{pc} = 1^{ - +} $的异国状态，最近由besiii Collaboration在$ j/ψ\toγηη'$中观察到。它的质量刚好低于$ k \ bar k_1（1400）$的阈值刺激了我们，以调查这种异国情调的状态是否可以解释为$ k \ bar k_1（1400）+$ c.c {分子}。使用One Boson交换模型，我们表明，对于$ k \ bar k_1（1400）$，$ j^{pc} = 1^{ - +} $可以通过在$ 2.5 $ gev $ 2.5 $ gev时获得动量$λ\ gtrsim 2 $ gev并产生与实验值相同的绑定值，从而使绑定在一起。在此分子图中，预测的分支比率$ \ mathrm {br}（η_1（1855）\to致η'）\约15 \％$与实验结果一致，这再次支持$η_1（1855）$的分子解释。相关系统，即$ k \ bar k_1（1400）$，带有$ j^{pc} = 1^{ - } $和$ k \ bar k_1（1270）$，带有$ j^{pc} = 1^{ - \ pm} $，也可以研究其中一些可以在未来的实验中搜索。
An exotic state with $J^{PC}=1^{-+}$, denoted by $η_1(1855)$, was observed by BESIII collaboration recently in $J/ψ\to γηη'$. The fact that its mass is just below the threshold of $K\bar K_1(1400)$ stimulates us to investigate whether this exotic state can be interpreted as a $K\bar K_1(1400)+$ c.c { molecule or not}. Using the one boson exchange model, we show that it is possible for $K\bar K_1(1400)$ with $J^{PC}=1^{-+}$ to bind together by taking the momentum cutoff $Λ\gtrsim 2$ GeV and yield the same binding energy as the experimental value when $Λ\approx 2.5$ GeV. In this molecular picture, the predicted branch ratio $\mathrm{Br}(η_1(1855)\toηη') \approx 15\%$ is consistent with the experimental results, which again supports the molecular explanation of $η_1(1855)$. Relevant systems, namely $K\bar K_1(1400)$ with $J^{PC}=1^{--}$ and $K\bar K_1(1270)$ with $J^{PC}=1^{-\pm}$, are also investigated, some of which can be searched for in the future experiments.
