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arXiv 2607.02438hep-phhep-exnucl-exnucl-th
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在 $e^+e^-$ 和 SIDIS 中的事件轴 TMD 测量

Event-axis TMD measurements in $e^+e^-$ and SIDIS

Universidad Complutense de Madrid(马德里康普顿斯大学);University of Amsterdam(阿姆斯特丹大学);Nikhef(尼黑理论物理研究所)

Daniel Diaz Fernandez, Patricia Andrea Gutierrez Garcia, Ignazio Scimemi, Wouter Waalewijn

AI总结:

研究通过测量相对于推力轴的强子来提取 TMD 碎裂函数,并扩展到 SIDIS 中的 TMD 部分子分布函数,提出非微扰模型并实现重求和,与 Pythia8.3 模拟数据对比验证。

摘要:

在 $e^+e^-$ 对撞中,可以通过测量相对于推力轴的强子来研究横向动量依赖(TMD)碎裂,这已在 Belle 实验中被测量。这提供了一种提取 TMD 碎裂函数的补充方法,避免了在传统的背对背强子对测量中需要区分两个 TMD 碎裂函数的问题。从该观测量已有的因子化定理出发,我们完成了软部分的算符级表述,并使用 $\delta$ 调节器进行了单圈检验。我们还扩展了半单举深度非弹性散射(SIDIS)中 1-喷注度因子化的现有结果,其中类似的测量可以获取入射强子的 TMD 部分子分布函数。在唯象学方面,我们讨论了非微扰效应,并提出了一个模型,该模型同时捕捉了事件形状依赖性和事件形状与横向动量测量之间的关联。我们对横向动量和推力对数进行重求和,探索了几种处理后者的方案,并在 artemide 中实现。作为首次验证,我们与来自 Pythia8.3 的模拟 $e^+e^-$ 数据进行了比较。我们发现所提出的非微扰模型足够灵活,能够描述模拟数据,拟合参数的大小符合 $\Lambda_{\rm QCD}/Q$ 的幂次预期。在此测试中,$q_T/(\tau Q)$ 对数的重求和似乎对拟合质量影响不大,但改变了拟合参数。

英文摘要:

Transverse-momentum-dependent (TMD) fragmentation in $e^+e^-$ collisions can be studied by measuring hadrons with respect to the thrust axis, and has been measured at Belle. This provides a complementary way to extract TMD fragmentation functions, avoiding the need to disentangle the two TMD fragmentation functions that enter conventional back-to-back hadron-pair measurements. Starting from the established factorization theorems for this observable, we complete the operator-level formulation of the soft ingredients and perform one-loop checks using the $δ$-regulator. We also extend existing results for 1-jettiness factorization in semi-inclusive deep-inelastic scattering (SIDIS), where analogous measurements give access to the TMD parton distribution functions of the incoming hadron. For phenomenology, we discuss the nonperturbative effects and propose a model that captures both the event-shape dependence and correlations between the event-shape and transverse-momentum measurements. We resum the transverse-momentum and thrust logarithms, explore several schemes for treating the latter, and implement it in artemide. As a first validation, we compare to simulated $e^+e^-$ data from Pythia8.3. We find that the proposed nonperturbative model is flexible enough to describe the simulated data, with fitted parameters of the expected size in powers of $Λ_{\rm QCD}/Q$. In this test, the resummation of the logarithms of $q_T/(τQ)$ appears to have little impact on the fit quality, but changes the fit parameters.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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