用横向动量截断分离准PDF中的方案依赖性
Anatomy of the Quasi-PDF with a Transverse-Momentum Cutoff
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中文总结 AI 辅助
研究利用横向动量截断将非单态夸克准PDF中与重整化相关的成分系统分解，阐述如何处理线性发散和对数项，明确方案依赖性在最终匹配前进入准PDF的方式，提供检验其他方案分离的基准。
中文摘要 AI 辅助
准PDF在格点QCD中的欧几里得空间关联与光锥部分子分布之间建立联系。其微扰表达式包含匹配所需的红外发散和与重整化规定相关的方案依赖贡献。本文用横向动量截断将这些成分系统分解，选择最小横向动量截断方案，展示如何处理反项中的线性发散和对数项，讨论重整化群行为对重整化规定的依赖性。
英文摘要
The quasi-PDF is fundamentally different from the light-cone PDF, and large-momentum effective theory relates the two through perturbative matching. This has required considerable effort. One of the difficulties in matching is that no single renormalization scheme has been agreed upon for the quasi-PDF, and the resulting variety of prescriptions can obscure the physics underlying the matching. We study how the choice of scheme affects the renormalized quasi-PDF and the matching coefficient, and how the two are related, aiming to identify a scheme in which this dependence becomes transparent. As a first attempt, we consider the transverse-momentum cutoff scheme. It is not used in practice, since a hard momentum cutoff breaks Lorentz invariance, and it has generally been treated as an illustrative example exhibiting the linear divergence of the spatial Wilson line. A careful study, however, reveals a richer structure than expected. The ultraviolet divergence in this scheme depends not only on the cutoff itself, but also on an independent divergence associated with the momentum fraction of the quasi-PDF. Disentangling these two ultraviolet structures, and following the disentangling through the explicit one-loop calculation, uncovers further structure along the way. Once the ultraviolet contributions are correctly separated and assigned to the renormalization counterterm, a finite ambiguity remains, and we use it to restore the quark-number conservation broken by the cutoff. The resulting renormalized quasi-PDF and matching coefficient can be meaningfully compared with the result obtained in dimensional regularization, and we show how the two are reconciled.
发表机构
- Korea University（韩国大学）
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