使用CLAS探测器测量$0.4$ GeV $^{2}$ $1.0$ GeV $^{2}$和PDMATHAAH GeV $< W <$ $1.825$ GeV的$γ_{v} p \rightarrow p' π^{+} π^{-}$横截面
Measurements of the $γ_{v} p \rightarrow p' π^{+} π^{-}$ cross section with the CLAS detector for $0.4$ GeV$^{2}$ $< Q^{2} <$ $1.0$ GeV$^{2}$ and $1.3$ GeV $< W <$ $1.825$ GeV
G. V. Fedotov, Iu. A. Skorodumina, V. D. Burkert, R. W. Gothe, K. Hicks, V. I. Mokeev, the CLAS Collaboration
备注：
22 pages, 22 figures, will be sent to Phys. Rev. C
新的结果上的单微分和全积分截面的过程$γ_{v} p \rightarrow p' π^{+} π^{-}$。实验数据是用杰斐逊实验室的CLAS探测器收集的。在运动学区域的反应不变质量$W$从1.3到1.825 GeV和光子虚$Q^2$从0.4到1.0 GeV $^2$进行测量。横截面中获得窄$Q^{2}$箱（0.05 GeV $^{2}$）与最小的统计不确定性达到双π介子电生产实验的日期。结果发现，在重叠的地方，与以前可用的数据一致。提取的截面，这是基于一个唯象的介子重子反应模型的初步解释，揭示了大量的相对贡献核子共振。这些数据提供了有前途的前景，以提高知识的$Q^{2}$ -进化的电耦合的大多数共振质量高达$\sim$ 1.8 GeV。
英文摘要：
New results on the single-differential and fully-integrated cross sections for the process $γ_{v} p \rightarrow p' π^{+} π^{-}$ are presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the kinematic region of the reaction invariant mass $W$ from 1.3 to 1.825 GeV and the photon virtuality $Q^2$ from 0.4 to 1.0 GeV$^2$. The cross sections were obtained in narrow $Q^{2}$ bins (0.05 GeV$^{2}$) with the smallest statistical uncertainties achieved in double-pion electroproduction experiments to date. The results were found to be in agreement with previously available data where they overlap. A preliminary interpretation of the extracted cross sections, which was based on a phenomenological meson-baryon reaction model, revealed substantial relative contributions from nucleon resonances. The data offer promising prospects to improve knowledge on the $Q^{2}$-evolution of the electrocouplings of most resonances with masses up to $\sim$1.8 GeV.
Production of $J/Ψ$ on the nucleon and deuteron targets
建立了一个包含$πN$、$ρN$和$J/ΨN$通道的耦合通道模型，并对$π+ N \rightarrow J/Ψ+ N $截面进行了计算。$J/Ψ$ - $N$相互作用的参数化形式与有效场论方法和格点QCD的预测有关。模型中的其他相互作用受到$J/Ψ\rightarrow ρ+ π$的衰变宽度和$πN$反应的总横截面数据的约束。计算的介子-重子振幅然后被用来预测的$J/Ψ$生产的氘靶的截面，包括从脉冲项和最终的$NN$和$J/ΨN$再散射效应的单圈计算的贡献。预测的$π^- + p \rightarrow J/Ψ+ n$，$γ+ d \rightarrow J/Ψ+ n + p$，和$π^+ d \rightarrow J/Ψ+p +p$的截面上的$J/Ψ$ - $N$的潜力的依赖性的$J/Ψ$-$N$相互作用的实验测定。在矢量介子优势模型中，我们还应用所建立的耦合通道模型预测了$J/Ψ$产生阈值附近的$γ+ p\rightarrow J/Ψ+ p$截面。
Partial-wave analysis of $\bar K N$ scattering reactions
我们通过单能分波分析研究了两体反应$\bar K N\rightarrow \bar K N$、$\bar K N\rightarrow πΛ$和$\bar K N\rightarrow πΣ$。能量范围1480 - 2100 MeV。因此，提取的这些反应的分波振幅的多通道能量依赖模型满足的分波$S$矩阵的么正性的约束。我们得到了很好的预测微分截面，极化，极化截面，和截面这些反应从一个全球性的能量依赖的解决方案。
