We introduce a string-based parametrization for nucleon quark and gluon generalized parton distributions (GPDs) that is valid for all skewness. Our approach leverages conformal moments, representing them as the sum of spin-j nucleon A-form factor and skewness-dependent spin-j nucleon D-form factor, derived from t-channel string exchange in AdS spaces consistent with Lorentz invariance and unitarity. This model-independent framework, satisfying the polynomiality condition due to Lorentz invariance, uses Mellin moments from empirical data to estimate these form factors. With just five Regge slope parameters, our method accurately produces various nucleon quark GPD types and symmetric nucleon gluon GPDs through pertinent Mellin-Barnes integrals. Our isovector nucleon quark GPD is in agreement with existing lattice data, promising to improve the empirical extraction and global analysis of nucleon GPDs in exclusive processes, by avoiding the deconvolution problem at any skewness, for the first time. Published by the American Physical Society 2024

中文翻译：

---

AdS 空间中来自 t 通道字符串交换的广义 Parton 分布的参数化


我们引入了一种基于字符串的参数化，用于核子夸克和胶子广义部分子分布 （GPD），它对所有偏度都有效。我们的方法利用共形矩，将它们表示为自旋-j 核子 A 形式因子和偏度依赖性自旋 j 核子 D 形式因子之和，这些因子来自 AdS 空间中的 t 通道字符串交换，与洛伦兹不变性和幺正性一致。这个独立于模型的框架满足洛伦兹不变性导致的多项式条件，使用来自经验数据的梅林矩来估计这些形状因子。仅使用五个 Regge 斜率参数，我们的方法通过相关的 Mellin-Barnes 积分准确生成各种核子夸克 GPD 类型和对称核子胶子 GPD。我们的等向量核子夸克 GPD 与现有的晶格数据一致，有望通过首次避免任何偏度下的反卷积问题，改进独家过程中核子 GPD 的经验提取和全局分析。 美国物理学会 2024 年出版