论文标题
朝向$ e^+e^ - \toπ^+π^ - $ $ρ$中态启发，大约2.2 GEV
Toward $e^+e^-\to π^+π^-$ annihilation inspired by higher $ρ$ mesonic states around 2.2 GeV
论文作者
论文摘要
最近，{\ it babar}的合作表明，重点关注$ e^+e^ - \toπ^+π^ - $ Process时，有一个明显的增强结构接近2.2 GEV，这激发了我们研究更高$ρ$ $ $ $ sesonic国家的兴趣。由于$π^+π^ - $ d $ wave $ρ$状态的分支比率远小于$ s $ wave状态，因此我们选择$ρ（1900）$和$ρ（2150）$作为$ e^+e^+e^+e^+e^ - \toπ^+π^+π^ - $ $ρ（1900）$ρ（3050）的中间状态$ρ（4s）$状态。我们的结果表明，$ e^+e^ - \toπ^+π^ - $大约2 GEV的$ babar $的数据可以很好地描绘，这表明这种增强结构接近$ e^+e^+e^+e^ - \toπ^+π^ - $的2.2 GEV可以是由于两个$ρ$ mesons的贡献，可以是造成的。此外，该结论可以通过$γ_{e^+e^ - } \ Mathcal {b}的提取值的一致性来实现，$ρ（1900）$和$ρ（2150）$在整个拟合过程和相应的理论计算中。 $ e^+e^ - \toπ^+π^ - $数据的本研究可能会提供有价值的信息来建立$ρ$ MESON家族。
Very recently, the {\it BABAR} Collaboration indicated that there exist an explicit enhancement structure near 2.2 GeV when focusing on the $e^+e^-\toπ^+π^-$ process again, which inspires our interest in studying the production of higher $ρ$ mesonic states. Since the branching ratio of $π^+π^-$ channel of $D-$wave $ρ$ states are much smaller than $S-$wave states, we choose $ρ(1900)$ and $ρ(2150)$ as the intermediate states in $e^+e^-\toπ^+π^-$, where $ρ(1900)$ and $ρ(2150)$ are treated as $ρ(3S)$ and $ρ(4S)$ states, respectively. Our result indicates that the $BABAR$'s data of $e^+e^-\toπ^+π^-$ around 2 GeV can be depicted well, which shows that this enhancement structure near 2.2 GeV existing in $e^+e^-\toπ^+π^-$ can be due to the contribution from two $ρ$ mesons, $ρ(1900)$ and $ρ(2150)$. Additionally, this conclusion can be enforced by the consistence of the extracted values of $Γ_{e^+e^-}\mathcal{B}(π^+π^-)$ of $ρ(1900)$ and $ρ(2150)$ in the whole fitting processes and the corresponding theoretical calculations. The present study of $e^+e^-\toπ^+π^-$ data may provide valuable information to establish the $ρ$ meson family.
