我们估计双光子交换过程的贡献$e^+ +e^- \to p + \bar{p}$。计算了类时区双自旋极化观测量和形状因子的双光子交换修正。修正的幅度很小，但在固定的动量转移有很强的角度依赖性。这两个特征与类空区中的特征相同。从实验的角度看，可观测到的双自旋极化$P_z$值得考虑。
英文摘要：
We estimate two-photon exchange contribution to the process $e^+ +e^- \to p + \bar{p}$. The two-photon exchange corrections to double spin polarization observables and form factors in the time-like region are calculated. The corrections are found to be small in magnitude, but with a strong angular dependence at fixed momentum transfer. These two features are the same as those in the space-like region. In the view of experiment, the double spin polarization observable $P_z$ deserves to be considered.
Proton induced $K^+$ production and the $s\bar{s}$ content of the proton
我们研究了在K介子阈值附近质子诱导的$K^+$的产生。比较两种模式：给出了两种模型的介子交换模型，包括$π$，ρ $, $ K $ and $ K^ \ast $ exchange, together with the dominant baryon resonances, and a quark-gluon model, where momentum sharing is provided via the exchange of two gluons. Based on covariant bound state wave functions for the meson and the baryons - which we treat as quark-diquark objects - first results for the $ pp \to p截面.
Production and Width of the Pentaquark Theta+(1540) in Strangeness Production in the Proton-Proton System
我们分析了最近关于强子反应pp -> p Sigma+ K 0中Theta+（1540）五夸克激发的实验信息。在描述了介子交换模型中作为标准化的常规产生过程的基础上，我们估算了介子-重子和夸克-胶子模型中K -交换引起的共振Theta+诱导截面和五夸克态的宽度.通过与实验的比较，我们得到了θ +的宽度，介子交换中的p θ + K 0耦合常数，以及θ +中核子-K原子团簇的相对s或p波函数.
Model Independent Considerations on Two-Photon Exchange in Electron Proton Scattering and in the Crossed Processes
本文用三个复振幅讨论了$ep$弹性散射和交叉过程（$\bar p +p\leftrightarrow \ell^+ +\ell^-$，$\ell=e$或$μ$）中双光子交换的存在，这三个复振幅是两个运动学变量的函数，即动量转移平方$q^2$和虚光子的偏振态$ε$。导出了微分截面和偏振观测量的模型无关表达式。特别注意的是，强子电磁形状因子的提取，这变得更加困难的存在下，双光子交换，以及相关的实验观测值，可以给这种机制的证据。
We propose a new model for a homogeneous description of hadron-hadron and hadron-nucleus collisions, the Gluon Exchange Model, fundamentally based on color octet (gluon) exchange. In proton-proton collisions we provide an exact description of the final state proton and neutron spectrum including the proton diffractive peak. In proton-nucleus reactions we find that the projectile proton diquark cannot survive in more than about half of multiple proton-nucleon processes and consequently must be very frequently disintegrated, leading to long transfers of baryon number over rapidity space.
A sharply peaked structure is found in the angular distribution of emitted $π^+$ mesons from the photon-proton collisions. It offers a possible way for generating a $π^+$-condensation in free space. To make the stimulated emission of $π^+$-mesons efficient, a ring resonator is designed.
Near threshold eta production in proton-proton collisions
假设质子-质子碰撞中近阈eta产生的总截面是由于一个核子发射出一个介子x（pi，eta，sigma），然后在第二个核子上发生xN-> etaN跃迁.在分析π N散射和π N --> eta N反应时，根据最近建立的幺正多通道多共振模型产生了x N --> eta N振幅。初始和最终的PP失真计算从耦合通道的π-NN模型描述的NN散射数据高达约2 GeV。采用波恩势的x-NN顶点函数，计算了阈pp --> eta pp反应的总截面，结果与实验数据符合较好.与以前的工作相比，我们发现，eta交换起着重要的作用。用σ交换模拟的两π介子交换的影响被发现是显著的，但不像以前的工作中引入的矢量介子交换那样占主导地位。
Strangeness production in proton-proton collisions
在包括π介子和K介子交换图的玻色子交换模型中计算了$K^+$或$K^0$介子与$Λ$或$Σ$超子的反应$pp \to N K Y$的截面.我们分析了输入$πN$幅度的准确性的结果的依赖性。通过固定$πNN $耦合常数和$πNN$顶点处的截止参数$Λ_π$，计算了K介子交换图的贡献，并通过与实验数据的拟合，得到了$KN Λ$和$KN Σ$耦合常数的比值。这个比值与SU（6）的预言是一致的。我们计算出的不同反应通道的总截面拟合简单的表达式，并与文献中使用的其他参数化。此外，还讨论了临界值附近生产截面的总体特征。
We use heavy baryon chiral perturbation theory to evaluate the two-photon exchange corrections to the low-energy elastic lepton-proton scattering at next-to-leading order accuracy, i.e., ${\mathcal O}(α, M^{-1})$, including a non-zero lepton mass. We consider the elastic proton intermediate state in the two-photon exchange together in the soft photon approximation. The infrared singular contributions are projected out using dimensional regularization. The resulting infrared singularity-free two-photon exchange contribution is in good numerical agreement with existing predictions based on stand…
The effect of axial meson exchange on extraction of proton electromagnetic form factors in $ep$ scattering is calculated. Taking as an example $f_1(1285)$ meson exchange, it is quantitatively shown how it affects Rosenbluth and polarization transfer methods. The contribution of an axial meson is negligible in comparison with the traditional box-type two photon exchange and could not be responsible for difference of form factors extracted by different techniques. However, results support the idea that meson exchange could explain deviation of individual polarizations.
We apply our recently formulated Gluon Exchange Model (GEM) to baryon production in proton-nucleus reactions involving N>1 proton-nucleon collisions. We propose a description scheme for the process of soft color octet (gluon) exchange, based on the assumption that probabilities to form an effective diquark are equal for all allowed pairs of quarks. The latter effective diquark can form either from two valence, one valence and one sea, or from two sea quarks. Consequently we calculate the probabilities for different color configurations involving diquarks of valence-valence, valence-sea and sea…
The effect of the self-energy on the photon-proton elastic scattering is investigated for the backward and the forward directions. The shape of the Thomson scattering at the photon energy $ω\to 0$ is broken by taking into account the self-energy of proton. The electromagnetic polarizabilities $\barα\pm\barβ$ are calculated by the lowest-order perturbative treatment.
