论文标题
$ \ cos 2ϕ $ azimuthal不对称$ρ^0 $梅森在超疗法的重型离子碰撞中的生产
The $\cos 2ϕ$ azimuthal asymmetry in $ρ^0$ meson production in ultraperipheral heavy ion collisions
论文作者
论文摘要
我们提出了一项详细的研究，该研究对超递层重离子碰撞（UPC）中的载体中膜光生殖产生生产。使用偶极子模型，我们为关节冲击参数和横向动量依赖的横截面开发了一个框架。我们计算了$ρ^0 $光增生性的$ρ^0 $光增生$ ϕ $定义为$ρ^0 $的横向动量与其其衰减产物Pion Meson的横向动量之间的角度，计算了$ρ^0 $光增生的$ρ^0 $光增生性的$ρ^0 $光增生性的$ρ^0 $光增生性。我们对非极化相干差异截面的结果为恒星实验数据提供了出色的描述。进行了理论计算与实验测量对$ \ cos 2ϕ $方位角不对称性（由线性极化光子产生的，并达到合理的一致性）之间的第一个比较。我们在RHIC和LHC能量上都发现了特征性的衍射模式，并通过考虑UPC和外围碰撞来预测$ρ^0 $ PHOTOPRODUCTION的影响参数$ \ cos 2ϕ $ azimuthal的不对称。与我们的计算相关的RHIC和LHC的未来实验测量将提供一种工具，以严格研究UPC中载体中媒介的连贯和不连贯的产生，并探测重离子碰撞中的核结构。
We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We compute the unpolarized cross section and $\cos 2ϕ$ azimuthal angular correlation for $ρ^0$ photoproduction with $ϕ$ defined as the angle between the $ρ^0$'s transverse momentum and its decay product pion meson's transverse momentum. Our result on unpolarized coherent differential cross section gives excellent description to the STAR experimental data. A first comparison between theoretical calculation and experimental measurement on the $\cos 2ϕ$ azimuthal asymmetry, which results from the linearly polarized photons, is performed and reasonable agreement is reached. We find out the characteristic diffractive patterns at both RHIC and LHC energies and predict the impact parameter dependent $\cos 2ϕ$ azimuthal asymmetries for $ρ^0$ photoproduction by considering UPCs and peripheral collisions. The future experimental measurements at RHIC and LHC relevant to our calculations will provide a tool to rigorously investigate the coherent and incoherent production of vector meson in UPCs, as well as to probe the nuclear structure in heavy ion collisions.
