论文标题
张量 - 托米龙方法中的虚拟康普顿散射
Deeply virtual Compton scattering in the tensor-pomeron approach
论文作者
论文摘要
先前提出的用于描述低$ x $ dis数据的两张tensor-pomeron模型应用于质子上的真实和虚拟康普顿散射。该模型包括两个张量的波美龙，一个柔软的和硬张量，以及张量的reggeon。我们包括横向和纵向虚拟光子的贡献。我们表明，该模型在HERA的Deeply Virtual Compton散射（DVC）上提供了对小Bjorken $ x $的实验数据的很好描述。 Reggeon交换项与描述在fnal的$γp$ unergies下测得的真实蛋白 - 普罗顿散射特别相关。我们提出了两种拟合，这些拟合在硬波梅隆贡献的强度上有所不同。在这两个拟合中，我们都发现软蛋白酶交换之间的干扰起着重要作用。我们发现，在DVC中，软蛋白酶的贡献最多可达$ q^{2} \ sim 20 $ gev $^{2} $。我们的模型允许研究从小$ q^{2} $制度的过渡，包括光生效（$ q^{2} = 0 $）的限制，到大 - $ q^{2} $制度，dist限制。我们还讨论了$γ^{*} p \与γp$的纵向和横向极化的虚拟光子的横截面的比率，这是$ | t | $和$ q^2 $的函数。比率$ \ \ tilde {r}（q^{2}，w^{2}，t）=（dσ_{\ rm l} / dt） /（dσ_ {\ rm t} / dt）$以$ t $的速度强烈增加。我们的发现可能会在低$ x $制度的未来Lepton-Nucleon散射实验中进行检查，例如，在BNL（EIC）的将来的电子离子对撞机上，如果实现LHEC，则可以在LHC上实现LHEC。
The two-tensor-pomeron model proposed previously to describe low $x$ DIS data is applied to real and virtual Compton scattering on a proton. The model includes two tensor pomerons, a soft and a hard one, and tensor reggeons. We include contributions of both transverse and longitudinal virtual photons. We show that this model gives a very good description of experimental data at small Bjorken $x$ on deeply virtual Compton scattering (DVCS) from HERA. The reggeon exchange term is particularly relevant for describing the real-photon-proton scattering measured at lower $γp$ energies at FNAL. We present two fits which differ somewhat in the strength of the hard pomeron contribution. In both fits we find that the interference between soft- and hard-pomeron exchange plays an important role. We find that in DVCS the soft-pomeron contribution is considerable up to $Q^{2} \sim 20$ GeV$^{2}$. Our model allows to study the transition from the small-$Q^{2}$ regime, including the photoproduction ($Q^{2} = 0$) limit, to the large-$Q^{2}$ regime, the DIS limit. We also discuss the ratio of cross sections for longitudinally and transversely polarized virtual photons in $γ^{*} p \to γp$ as a function of $|t|$ and $Q^2$. The ratio $\tilde{R}(Q^{2},W^{2},t) = (dσ_{\rm L} / dt) / (dσ_{\rm T} / dt)$ strongly increases with $t$. Our findings may be checked in future lepton-nucleon scattering experiments in the low-$x$ regime, for instance, at a future Electron-Ion Collider at the BNL (EIC), and, if LHeC is realized, at the LHC.
