论文标题
质子几何形状在独家媒介膜产生中的能量依赖性
Energy dependence of the proton geometry in exclusive vector meson production
论文作者
论文摘要
预计质子的Gluon半径有望在小的Gluon动量分数$ x $上增加，迄今尚未在偶极模型框架中考虑的效果。我们通过引入三种型号的$ x $依赖性Gluon厚度功能，研究了独家$ J/ψ$，$ ϕ $和$ρ$生产的能源依赖性。我们允许质子的横向宽度随着$ x $的减少而增加，使用球形质子和热点模型中的新参数化。我们将这些模型进行比较，其中热点数量随着$ x $的减少并与HERA数据相遇而增加。这些模型在$ t $ spectra的斜率以及连贯和不连贯事件之间的横截面比率上表现出明显的差异。与$ t $ -Slopes和$ W_ {γp} $测量值的比较表明，质子大小随$ x $减小而增加的模型的偏好。
The gluon radius of the proton is expected to increase at small gluon momentum fractions $x$, an effect which has hitherto not been considered in the dipole model framework. We investigate the energy dependence of exclusive $J/ψ$, $ϕ$, and $ρ$ production by introducing three models for $x$ dependence of the gluon thickness function. We allow the transverse width of the proton to increase as $x$ decreases, using novel parametrisations in the spherical proton and the hotspot model. We compare these with a model where the number of hotspots increases as $x$ decreases and confront the models with HERA data. The models exhibit clear differences in the slope of the $t$-spectra and in the cross section ratios between coherent and incoherent events. Comparisons to $t$-slopes and $W_{γp}$ measurements show a preference for models where the proton's size increases as $x$ decreases.
