We calculate the q q correlation function associated to transverse target lepton-nucleon inclusive deep-inelastic scattering by direct evaluation of the corresponding matrix element. We use the electromagnetic impact parameter potential for a transversely polarized nucleon to define the q q correlation function for each avor in terms of the field components of that avor. The results are compared with the two existing models for the q q correlator. Using the calculated q q correlation function, we estimated the transverse target SSA in IDIS process.
In this paper, we discuss the new hard pole contribution to the $P_{h\perp}$-weighted single-transverse spin asymmetry in semi-inclusive deep inelastic scattering. We perform the complete next-to-leading order calculation of the $P_{h\perp}$-weighted cross section and show that the new hard pole contribution is required in order to obtain the complete evolution equation for the Qiu-Sterman function derived by different approaches.
We compute the single-spin asymmetry $A_{UL}$ in semi-inclusive deep-inelastic scattering of unpolarized leptons and longitudinally polarized protons at large transverse momentum of the produced hadron. Our calculation is performed in collinear factorization at the lowest order of QCD perturbation theory. For photon exchange the asymmetry is T-odd and receives contributions from the interference of the tree level and one-loop absorptive amplitudes. We consider the behavior of the spin asymmetry at low transverse momentum where contact to the formalism based on transverse-momentum dependent dis…
Predictions for hadron polarizations and left-right asymmetry in inclusive reactions involving photons
一个唯象模型，其中有一些成功的解释极化现象和左右不对称的包容性质子-质子散射被认为是涉及光子的反应。特别地，考虑了反应（a）$ γ+ p \to H + X;$（b）$γ+ p (\uparrow) \to π^{\pm} + X $和（c）$p(\uparrow) + p \to γ+ X$，其中$γ=$分辨光子和超子$ H = Λ^0, Σ^{\pm}$等。（a）中超子极化的预测和（b）和（c）中的不对称性提供了对该特定模型的进一步检验。简要讨论了在HERA观测（b）的可行性和海水极化对$p (\uparrow) + p \to π^{\pm} + X$质子的影响。
Theoretical Update of Twist-3 Single-Spin Asymmetry in Semi-Inclusive DIS
基于与大横动量π介子产生相关的共线因子分解中的twist-3机制，讨论了半包容DIS（$e p^\uparrow \to e πX$）中的单自旋不对称性.这更新了我们以前的研究，包括，特别是，新的部分子过程引起的贡献，并允许我们推导出完整的公式为相应的单自旋不对称性与一套完整的扭曲3夸克胶子关联函数在横向极化核子。我们讨论了与低横动量π介子产生的横动量相关因子分解结果的对应关系。
In this paper we study the single longitudinal spin asymmetry $A_{UL}^{\sin(ϕ_h-ϕ_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) via helicity-dependent dihadron fragmentation function (DiFF), which describes the correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair. Recently experimental searching for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration yielded a very small signal. Here we calculate this unknown T-odd DiFF $G_1^\perp$ using a spectator model to access the a…
Nuclear dependence of azimuthal asymmetry in semi-inclusive deep inelastic scattering
在广义因式分解的框架下，半包容深度非弹性散射（SIDIS）截面可以表示为共线硬部分和横动量相关（TMD）部分子分布和关联的乘积.研究了方位角不对称性<cos θ> $ of unpolarized SIDIS in the small transverse momentum region will depend on both twist-2 and 3 TMD quark distributions in target nucleons or nuclei. Nuclear broadening of these twist-2 and 3 quark distributions due to final-state multiple scattering in nuclei is investigated and the nuclear dependence of the azimuthal asymmetry $ < \cos θ>$。结果表明，方位角不对称性被多部分子散射抑制，抑制的横向动量依赖于核子中扭曲2和3夸克分布的相对形状。本文利用核子中TMD扭曲2和3夸克分布的高斯近似，证明了方位角不对称性的核依赖性，并估计了碎裂引起的拖尾效应。
Transverse momentum asymmetry in the semi-inclusive electron positron annihilation process
College of Nuclear Equipment and Nuclear Engineering, Yantai University（烟台大学核装备与核工程学院）；School of Physics and Optoelectronic Engineering, Shandong University of Technology（山东理工大学物理与光电工程学院）；Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences（中国科学院现代物理研究所南方核科学理论中心）；Key Laboratory of Particle Physics and Particle Irradiation (MOE), Institute of Frontier and Interdisciplinary Science, Shandong University（山东大学前沿交叉科学高等研究中心粒子物理与粒子辐照教育部重点实验室）
The single longitudinal spin asymmetry $A_{UL}^{\sin(2ϕ_h-2ϕ_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) is examined through helicity-dependent dihadron fragmentation function (DiFF) $G_1^\perp$. The correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair is illustrated by this DiFF. The experimental investigation for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration has lately yielded a very small signal. Here, the unknown T-odd dihadron fragmentation function $G_1^\pe…
We study the single spin asymmetry in the transversely polarized proton production and the lambda hyperon production in semi-inclusive deep inelastic scattering with a $\sin ϕ_{S_h}$ modulation, in which $S_h$ is the azimuthal angle of the transverse spin of the final hadron. The theoretical interpretation for the asymmetry is presented as the convolution of the twist-3 quark transverse momentum dependent distributions and twist-2 fragmentation functions. We investigate the role of the twist-3 distribution functions $h(x, p_T^2)$, $f^\perp(x, p_T^2)$ and $g^\perp(x, p_T^2)$ and the twist-2 fra…
Flavor asymmetry of polarized antiquark distributions and semi-inclusive DIS
QCD的$1/N_c$ -展开式表明核子中极化反夸克分布的大味不对称性。这是证实了在大$N_c$极限（手征夸克孤子模型），这给出了相当大的结果$Δ\bar u (x) - Δ\bar d (x)$和$Δ\bar u (x) + Δ\bar d (x) - 2 Δ\bar s (x)$模型计算。我们计算了这些味不对称性的贡献，在强子生产的自旋不对称性在半包容的深度非弹性散射。我们表明，大味不对称性预测的手征夸克孤子模型是一致的，与最近的HERMES数据的自旋不对称性带电强子生产。
This paper presents perturbative QCD predictions of the electron charge asymmetry for the inclusive $W^{\pm}+X \rightarrow e^{\pm} ν+X$ production in proton-proton (pp) collisions. Perturbative QCD calculations are performed at next-to-next-to-leading order (NNLO) accuracy by using different parton distribution function (PDF) models at 8 TeV, 13 TeV, and 14 TeV center-of-mass energies of the CERN LHC pp collisions. The NNLO calculations are performed for the electrons to have transverse momentum more than 20 GeV in the forward electron pseudorapidity region $2.0 \leq η_{e} \leq 4.25$. The NNLO…
We calculate the target normal single-spin asymmetry caused by two-photon exchange in inclusive electron-nucleon scattering in the resonance region. Our analysis uses the $1/N_c$ expansion of low-energy QCD and combines $N$ and $Δ$ intermediate and final states using the contracted $SU(4)$ spin-flavor symmetry. The normal spin asymmetry obtained in leading-order accuracy in $1/N_c$ has magnitude $\sim 10^{-2}$ and different sign in $ep$ and $en$ scattering. It can be measured in electron scattering at lab energies $\sim$ 0.5-1.5 GeV and provides a clean probe of two-photon exchange dynamics.
We study the semi-inclusive production of real, high-$p_T$, isolated photons in unpolarized and polarized lepton-proton collisions, $\ell p\to \ellγX$. In particular we analyze the transverse nucleon single-spin asymmetry within the collinear twist-3 formalism in perturbative QCD to leading order (LO) accuracy. We find that this spin asymmetry is generated by twist-3 dynamical quark-gluon-quark ($qgq$) correlations in the nucleon through the so-called soft-fermion and hard pole contributions. Hence, this process unprecedentedly allows for a point-by-point scan of the support of the dynamical $…
