论文标题
$ x（3872）$质量的可能的精确度量与$ e^+e^ - \toπ^0γX（3872）$和$ p \ bar p \toγx（3872）$ reactions
Possible precise measurements of the $X(3872)$ mass with the $e^+e^-\toπ^0γX(3872)$ and $p\bar p\toγX(3872)$ reactions
论文作者
论文摘要
最近有人提出，$ x（3872）$绑定能量，$ d^0 \ bar d^{*0} $阈值与$ x（3872）$ smos，可以通过测量$γx（3872）$线的形状来确切确定。实验。在这里，我们通过估计$ e^+e^ - \toπ^0γX（3872）$和$ p \ bar p \toγx（3872）$过程的$ e^+e^ - \toπ^0γX（3872）$过程来调查此类建议的可行性。 d^0 $三角循环。这些循环可以在$ d^{*0} \ bar d^{*0} $ threshold上方产生三角形奇异性。发现源自$ d^{*0} \ bar d^{*0} $阈值cusp和三角形奇点的峰结构并没有通过$ e e^+e^+e^ - \toπ^0d^0d} 0} 0} \ bar d^{*0} $ p \ p \ p \ bar介绍的能量依赖性而发生太大变化。 d^{*0} d^{*0} $生产零件或考虑$ x（3872）$的有限宽度。我们发现$σ（e^+e^ - \toπ^0γX（3872））\ times {\ rm br}（x（x（3872）\toπ^+π^+π^-J/ψ）$ as $ \ nathcal {o}（0.1〜 {0.1〜 {\ rm fb}）$ cobs $ $ uny1 $ coun $γ2 4.02 GEV和C.M. $ e^+e^ - $对的能量固定为4.23 GEV。横截面$σ（p \ bar p \toγx（3872））\ times {\ rm br}（x（3872）\toπ^+π^-J/ψ）$估计为$ \ Mathcal {O}（O}（O}（10〜 {\ rm pb}））$。我们的结果表明，可以在Panda进行$ X（3872）$绑定能量的精确度量。
It was recently proposed that the $X(3872)$ binding energy, the difference between the $D^0\bar D^{*0}$ threshold and the $X(3872)$ mass, can be precisely determined by measuring the $γX(3872)$ line shape from a short-distance $D^{*0}\bar D^{*0}$ source produced at high-energy experiments. Here, we investigate the feasibility of such a proposal by estimating the cross sections for the $e^+e^-\toπ^0γX(3872)$ and $p\bar p\toγX(3872)$ processes considering the $D^{*0}\bar D^{*0}D^0/\bar D^{*0}D^{*0}\bar D^0$ triangle loops. These loops can produce a triangle singularity slightly above the $D^{*0}\bar D^{*0}$ threshold. It is found that the peak structures originating from the $D^{*0}\bar D^{*0}$ threshold cusp and the triangle singularity are not altered much by the energy dependence introduced by the $e^+e^-\toπ^0D^{*0}\bar D^{*0}$ and $p\bar p\to\bar D^{*0}D^{*0}$ production parts or by considering a finite width for the $X(3872)$. We find that $σ(e^+e^-\toπ^0γX(3872)) \times {\rm Br}(X(3872)\toπ^+π^-J/ψ)$ is $\mathcal{O}(0.1~{\rm fb})$ with the $γX(3872)$ invariant mass integrated from 4.01 to 4.02 GeV and the c.m. energy of the $e^+e^-$ pair fixed at 4.23 GeV. The cross section $σ(p\bar p\toγX(3872))\times {\rm Br}(X(3872)\toπ^+π^-J/ψ)$ is estimated to be of $\mathcal{O}(10~{\rm pb})$. Our results suggest that a precise measurement of the $X(3872)$ binding energy can be done at PANDA.
