Nucleon Structure and Hadronization Beyond the Collinear Leading Twist Parton Model

超越共线引导扭曲帕顿模型的核子结构和强子化

• 批准号: 1912522
• 负责人: Michael Engelhardt
• 金额: $ 27万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-15 至 2023-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1912522&HistoricalAwards=false
• 关键词: Nucleon; Structure; Hadronization; Beyond; Collinear

It has been a long-standing question in nuclear physics of how the nucleon, the main building block of the matter that we are made of, is built from fundamental strongly-interacting elementary particles, the quarks and gluons. This project will address this question by studying correlations and 3-dimensional momentum distributions of quarks and gluons in the nucleon. To this end experimentally measurable observables are theoretically analyzed for nuclear reactions that can be realized at US-based facilities like the Jefferson Laboratory (JLab), the Relativistic Heavy Ion Collider (RHIC), and the future Electron-Ion Collider (EIC), as well as other facilities worldwide. The underlying microscopic theory on which this research is based is Quantum Chromodynamics (QCD). Several observables that are of interest for this project need spin polarization of the beam or the target, or even the produced final state particles. The theoretical analyses of those spin observables require methods and precision calculations that go beyond the common standard theoretical approaches for unpolarized nuclear reactions. The PI will mentor graduate students and include an undergraduate student in this research program.The main goal of this project is a theoretical investigation of the nucleon structure as well as parton fragmentation within perturbative QCD. It is intended to study observables of high-energy nuclear processes beyond the standard leading twist collinear factorization approach. The focus is on two key areas: 1) Transverse spin effects in single-inclusive nuclear processes within the collinear twist-3 formalism. 2) Transverse momentum dependent gluon distributions in polarized and unpolarized proton collisions. The outcome of these studies will have direct impact for experimental programs at JLab, RHIC, the Large Hadron Collider (LHC), and a future EIC. The main thrusts of the project are: i) Theoretical analyses of transverse spin-polarized observables in single-inclusive nuclear reactions in the framework of collinear twist-3 formalism: The goal is to perform next-to-leading (NLO) calculations for transverse-spin observables and to study the scale dependence of three-parton correlation functions. Furthermore, the PI will investigate the feasibility of photonic final state in lepton-nucleon collisions at JLab and EIC; ii) Exploration of the gluonic substructure of the nucleon within Transverse Momentum Dependent (TMD) factorization: TMD analyses of various gluon-induced spin observables in proton-proton collisions at RHIC with Heavy Quarkonia in the final state are considered including implementation of TMD evolution.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在核物理学中，这是一个长期存在的问题，即核子是如何建立在根本上强烈相互互动的基本颗粒，夸克和胶子的基本问题的主要基础上的。该项目将通过研究核子中夸克和胶子的相关性和三维动量分布来解决这个问题。为此，在理论上对实验可测量的可观察物进行了可观察到的核反应，该核反应可以在美国杰斐逊实验室（JLAB），相对论重离子撞机（RHIC）和未来的电子碰撞器（EIC）以及其他全球其他设施中实现。这项研究所基于的基本微观理论是量子染色体动力学（QCD）。该项目感兴趣的几个可观察物需要梁或目标的自旋极化，甚至需要产生的最终状态颗粒。这些自旋可观察物的理论分析需要方法和精度计算，这些方法超出了对非核化核反应的通用标准理论方法的范围。 PI将指导研究生，并在本研究计划中包括一名本科生。该项目的主要目标是对核子结构以及扰动QCD中的Parton碎片进行理论研究。它旨在研究超出标准领先扭曲共线化方法的高能核过程的可观察情况。重点是两个关键领域：1）在线扭曲3形式主义内单包核过程中的横向自旋效应。 2）在极化和非极化质子碰撞中，横向动量依赖性的Gluon分布。这些研究的结果将对JLAB，RHIC，大型强子对撞机（LHC）和未来EIC的实验计划产生直接影响。 该项目的主要目的是：i）在共线式扭曲-3形式主义的框架中，在单包核反应中对横向自旋的可观察力的理论分析：目标是对横向旋转可观察物进行次数的计算（NLO）计算，并研究三分线相关功能的规模依赖性。此外，PI将研究光子最终状态在Jlab和EIC的Lepton-Nucleon碰撞中的可行性。 ii）探索横向动量依赖性（TMD）分解中核子的粘液性亚结构：TMD分析在RHIC的Proton-Proton在最终状态下与Quarkonia的Proton-Proton碰撞中各种旋转可观察结果的分析被视为最终状态中的重Quarkonia，包括通过TMD的实施来实施NSF的Internution deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem deem apptir。更广泛的影响审查标准。

项目成果

The transverse nucleon single-spin asymmetry for the semi-inclusive production of photons in lepton-nucleon scattering

• DOI: 10.1016/j.physletb.2020.135367
• 发表时间: 2019-10
• 期刊: Physics Letters B
• 影响因子: 4.4
• 作者: W. S. Albaltan;A. Prokudin;M. Schlegel

Studies of gluon TMDs and their evolution using quarkonium-pair production at the LHC

• DOI: 10.1140/epjc/s10052-020-7619-1
• 发表时间: 2019-09
• 期刊: The European Physical Journal C
• 作者: F. Scarpa;D. Boer;M. G. Echevarria;J. Lansberg;C. Pisano;M. Schlegel