Measurement of the J / ψ photoproduction cross section over the full near-threshold kinematic region
Measurement of the J / ψ photoproduction cross section over the full near-threshold kinematic region
复制标题
测量整个近阈值运动区域的 J / Ï 光制作横截面
DOI：
10.1103/physrevc.108.025201
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发表时间：
2023
影响因子：
3.1
通讯作者：
Barbosa, F.
中科院分区：
文献类型：
--
作者：
Adhikari, S.;Afzal, F.;Akondi, C. S.;Albrecht, M.;Amaryan, M.;Arroyave, V.;Asaturyan, A.;Austregesilo, A.;Baldwin, Z.;Barbosa, F.
我们报道了大接受GlueX能谱仪在8.2GeV到11.44GeV的阈值和整个动量传递平方运动范围内的光生总截面和微分截面。这样的覆盖便于在物理区域之外外推从前()点到前()点的不同横截面。正截面被许多理论模型所使用，在理解光产生及其与质子相互作用的关系中起着重要作用。这些阈值附近的光产生测量也是用于研究质子胶子结构的重要方面的理论模型的重要输入，例如质子的胶子广义部分子分布，质子的质量半径，以及踪迹反常对质子质量的贡献。我们在能量依赖的总截面上观察到了可能的结构，并在接近阈值的微分截面上找到了胶子交换以外的贡献的证据，这两者都与开放魅力中间态的贡献是一致的。
We report the total and differential cross sections forphotoproduction with the large acceptance GlueX spectrometer for photon beam energies from the threshold at 8.2 GeV up to 11.44 GeV and over the full kinematic range of momentum transfer squared,. Such coverage facilitates the extrapolation of the differential cross sections to the forward () point beyond the physical region. The forward cross section is used by many theoretical models and plays an important role in understandingphotoproduction and its relation to the-proton interaction. These measurements ofphotoproduction near threshold are also crucial inputs to theoretical models that are used to study important aspects of the gluon structure of the proton, such as the gluon generalized parton distribution of the proton, the mass radius of the proton, and the trace anomaly contribution to the proton mass. We observe possible structures in the total cross section energy dependence and find evidence for contributions beyond gluon exchange in the differential cross section close to threshold, both of which are consistent with contributions from open-charm intermediate states.