The forward limit of the chiral-odd generalized parton distributions (GPDs) and their lower moments are investigated within the framework of the chiral quark soliton model (CQSM), with particular emphasis upon the transversity decomposition of nucleon angular momentum proposed by Burkardt. A strong correlation between quark spin and orbital angular momentum inside the nucleon is manifest itself in the derived second moment sum rule within the CQSM, thereby providing with an additional support to the qualitative connection between chiral-odd GPDs and the Boer-Mulders effects. We further confirm isoscalar dominance of the corresponding first moment sum rule, which indicates that the Boer-Mulders functions for the $u$- and $d$-quarks have roughly equal magnitude with the same sign. Also made are some comments on the recent empirical extraction of the tensor charges of the nucleon by Anselmino et al. We demonstrate that a comparison of their result with any theoretical predictions must be done with great care, in consideration of fairly strong scale dependence of tensor charges, especially at lower renormalization scale.
Transversity generalized parton distributions (GPDs) appear as scalar functions in the decomposition of off-forward quark-quark and gluon-gluon correlators with a parton helicity flip. For a spin 1 hadron, we find 9 transversity GPDs for both quarks and gluons at leading twist 2. We study these twist-2 chiral odd quark transversity GPDs for the deuteron in a light cone convolution model, based on the impulse approximation, and using the lowest Fock-space state for the deuteron.
Transversity Generalized Parton Distributions from gamma N -> pi rhot N' with a Large pi rhot Invariant Mass
只要矢量介子是在横向极化态下产生的，无论有无束和靶的极化，都可以通过γ N → π ρ T N '的光生排斥过程，从实验上得到手征奇横向广义部分子分布.因子分解的运动学域通过介子对的大不变质量和末态核子的小横动量来定义。基于双分布的概念，我们微扰地计算了首阶的散射振幅，并建立了主导横向GPD H_T（x，xi，t）的简单模型。正在估算计数率。
We present the first direct calculation of the transversity parton distribution function within the nucleon from lattice QCD. The calculation is performed using simulations with the light quark mass fixed to its physical value and at one value of the lattice spacing. Novel elements of the calculations are non-perturbative renormalization and extraction of a formula for the matching to light-cone PDFs. Final results are presented in the $\overline{\rm MS}$ scheme at a scale of $\sqrt{2}$ GeV.
We present a determination of the non-singlet transversity parton distribution function (PDF) of the nucleon, normalized with respect to the tensor charge at $μ^2=2$ GeV$^2$ from lattice quantum chromodynamics. We apply the pseudo-distribution approach, using a gauge ensemble with a lattice spacing of 0.094 fm and the light quark mass tuned to a pion mass of 358 MeV. We extract the transversity PDF from the analysis of the short-distance behavior of the Ioffe-time pseudo-distribution using the leading-twist next-to-leading order (NLO) matching coefficients calculated for transversity. We recon…
Accessing nucleon transversity with one-point energy correlators
Fudan University（复旦大学）；University of California, Los Angeles（加州大学洛杉矶分校）；Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles（加州大学洛杉矶分校马尼·L·巴乌米克理论物理研究所）；Center for Frontiers in Nuclear Science, Stony Brook University（纽约州立大学石溪分校核科学前沿中心）；Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University（复旦大学核物理与离子束应用教育部重点实验室）；Shanghai Research Center for Theoretical Nuclear Physics, NSFC and Fudan University（国家自然科学基金委与复旦大学上海理论核物理研究中心）；Center for High Energy Physics, Peking University（北京大学高能物理中心）
Simplified approach to extracting nucleon transversity in collinear factorization using near-side energy-energy correlators
University of California, Los Angeles（加州大学洛杉矶分校）；Mani L. Bhaumik Institute for Theoretical Physics, University of California, Los Angeles（加州大学洛杉矶分校马尼·L·巴乌米克理论物理研究所）；Center for Frontiers in Nuclear Science, Stony Brook University（石溪大学核科学前沿中心）；Temple University（天普大学）；Lebanon Valley College（黎巴嫩谷学院）
Photoproduction of a pi rhoT pair with a large invariant mass and transversity generalized parton distribution
核子的手征奇横向广义部分子分布（GPD）可以通过光生过程gamma + N -> pi + rho + N '在运动学中得到，其中介子对具有大的不变质量，末态核子具有小的横向动量，只要矢量介子产生于横向极化态.我们用微扰法计算了首阶的散射振幅。基于双分布的概念，建立了显性横向GPD H_T（x，xi，t）的简单模型。我们估计的非极化微分截面为这个过程中的运动学的Jlab和COMPASS实验。计数率表明，实验看起来可行的真实光子束的特性预期在JLab@12 GeV，并与准真实光子束在COMPASS实验。
Dynamical gluon effects in proton transversity and off-forward parton distributions from a light-front Hamiltonian approach
Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Iowa State University（爱荷华州立大学）
Transverse Charge Distribution as a Probe of Nucleon Transversity
Fudan University（复旦大学）；Beijing Normal University（北京师范大学）；Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；Peking University（北京大学）
We report on the first global QCD analysis of the quark transversity distributions in the nucleon from semi-inclusive deep-inelastic scattering (SIDIS), using a new Monte Carlo method based on nested sampling and constraints on the isovector tensor charge $g_T$ from lattice QCD. A simultaneous fit to the available SIDIS Collins asymmetry data is compatible with $g_T$ values extracted from a comprehensive reanalysis of existing lattice simulations, in contrast to previous analyses which found significantly smaller $g_T$ values. The contributions to the nucleon tensor charge from $u$ and $d$ qua…
We present results on the quark unpolarized, helicity and transversity parton distributions functions of the nucleon. We use the quasi-parton distribution approach within the lattice QCD framework and perform the computation using an ensemble of twisted mass fermions with the strange and charm quark masses tuned to approximately their physical values and light quark masses giving pion mass of 260 MeV. We use hierarchical probing to evaluate the disconnected quark loops. We discuss identification of ground state dominance, the Fourier transform procedure and convergence with the momentum boost.…
We report a state-of-the-art lattice calculation of the isovector quark transversity distribution of the proton at the physical pion mass. Within the framework of large-momentum effective theory (LaMET), we compute the transversity quasi-distributions using clover valence fermions on 2+1+1-flavor (up/down, strange, charm) HISQ-lattice configurations with boosted proton momenta as large as 3.0~GeV. The relevant lattice matrix elements are nonperturbatively renormalized in regularization-independent momentum-subtraction (RI/MOM) scheme and systematically matched to the physical transversity dist…
$q \to Λ$ Fragmentation Function and Nucleon Transversity Distribution in a Diquark Model
基于一个简单的夸克-双夸克模型，通过拟合$e^+ e ^- $湮灭过程中的非极化$Λ$产生数据，提出了一组非极化、纵向极化和横向极化的$Λ$碎裂函数.结果发现，螺旋度结构的$Λ$碎裂功能的支持所有可用的实验数据的纵向$Λ$极化。在双夸克模型的同一框架内，核子的横向分布和一致的描述的方位角自旋不对称性的π电产生的HERMES数据。此外，还预测了横向极化核子靶上带电轻子DIS中横向极化$Λ$的自旋转移。
Nucleon spin structure functions have been investigated mainly by longitudinally-polarized ones for finding the origin of the nucleon spin. Other types of spin structure functions are transversely-polarized ones. In particular, quark transversity distributions in the nucleons have very different properties from the longitudinally-polarized quark distribution functions, especially in scaling violation, because they are decoupled from the gluon transversity, due to the fact that they are helicity-flip (chiral-odd) distributions. Such studies are valuable for finding not only the origin of the nu…
The transversity and the tensor charge of the nucleon, currently under active investigation experimentally and theoretically, are fundamental quantities in hadron physics as well as for our comprehension of the nucleon structure. Some tension between the values of the tensor charge, as computed on the basis of phenomenological extractions and lattice QCD calculations, has been observed. In this letter, by means of an explicit example, we study the role of assumptions, usually adopted in phenomenological parametrizations, and we show that, by relaxing some of them, such a tension could be eased…
