检索结果-内蒙古大学图书馆

Updated analyses of gluon distribution functions for the pion and kaon from the gauge-invariant nonlocal chiral quark model

引用

Physical Review D 2024年第5期109卷 054040-054040页

作者： Parada. T. P. Hutauruk Seung-il Nam Department of Physics Pukyong National University (PKNU) Busan 48513 Korea Department of Physics Education Daegu University Gyeongsan 39453 Korea Center for Extreme Nuclear Matters (CENuM) Korea University Seoul 02841 Korea Asia Pacific Center for Theoretical Physics (APCTP) Pohang 37673 Korea

In this work, we investigate the gluon distribution functions for the pion and kaon, in addition to the improved result of the valence-quark ones, in the gauge-invariant nonlocal chiral-quark model, in which the momentum dependence of the quark interactions is properly taken into account. We then analyze the gluon distribution functions, generated dynamically through the splitting functions in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi QCD evolution. By comparing with the recent lattice QCD results and Jefferson Lab angular momentum global analyses, it is found that the present numerical results for the gluon parton distribution functions for the pion exhibit a good agreement and the valence up-quark distribution results for the pion by reproducing the reanalyzed experimental data with a remarkable agreement. Our prediction on the gluon distribution functions for the kaon is also consistent with the recent lattice data for the kaon within the errors.

关键词： Instantons Nonrelativistic QCD parton distribution functions Gluons Mesons Quarks

来源：评论

学校读者我要写书评

暂无评论

Significance of radiative corrections on measurements of the EMC effect

引用

Physical Review C 2024年第2期110卷 025202-025202页

作者： S. Moran M. Arratia J. Arrington D. Gaskell B. Schmookler Department of Physics and Astronomy Berkeley California 94720 USA Newport News Virginia 23606 USA

Deep inelastic scattering from nuclear targets probes the parton distribution functions (PDFs) in nuclei. Comparisons of the PDFs from heavy nuclei and the deuteron show deviations that demonstrate a nontrivial nuclear dependence to these distributions, referred to as the EMC effect. A global analysis of the world's data on the EMC effect reveals tensions between different extractions. Precise measurements at Jefferson Lab, studying the dependence on both the quark momentum fraction, x, and nuclear mass, show systematic discrepancies among experiments, making the extraction of the A dependence of the EMC effect sensitive to the selection of datasets. By comparing various methods and assumptions used to calculate radiative corrections, we have identified differences that, while not large, significantly impact the EMC ratios and show that using a consistent radiative correction procedure resolves this discrepancy, leading to a more coherent global picture and allowing for a more robust extraction of the EMC effect for infinite nuclear matter.

关键词： Deep inelastic scattering Electroweak radiative corrections Nuclear matter parton distribution functions

来源：评论

学校读者我要写书评

暂无评论

Generalized parton distributions from the pseudodistribution approach on the lattice

引用

Physical Review D 2024年第5期110卷 054502页

作者： Shohini Bhattacharya Krzysztof Cichy Martha Constantinou Andreas Metz Niilo Nurminen Fernanda Steffens Theoretical Division Faculty of Physics Department of Physics Institut für Strahlen- und Kernphysik

Generalized parton distributions (GPDs) are key quantities for the description of a hadron’s three-dimensional structure. They are the current focus of all areas of hadronic physics—phenomenological, experimental and theoretical, including lattice QCD. Synergies between these areas are desirable and essential to achieve precise quantification and understanding of the structure of, particularly, nucleons, as the basic ingredients of matter. In this paper, we investigate, for the first time, the numerical implementation of the pseudodistribution approach for the extraction of zero-skewness GPDs for unpolarized quarks. Pseudodistributions are Euclidean parton correlators computable in lattice QCD that can be perturbatively matched to the light-cone parton distributions of interest. Although they are closely related to the quasidistributions and come from the same lattice-extracted matrix elements, they are, however, subject to different systematic effects. We use the data previously utilized for quasi-GPDs and extend it with other momentum transfers and nucleon boosts, in particular a higher one (P3=1.67 GeV) with eightfold larger statistics than the largest one used for quasidistributions (P3=1.25 GeV). We renormalize the matrix elements with a ratio scheme and match the resulting Ioffe time distributions to the light cone in coordinate space. The matched distributions are then used to reconstruct the x dependence with a fitting Ansatz. We investigate some systematic effects related to this procedure, and we also compare the results with the ones obtained in the framework of quasi-GPDs. Our final results involve the invariant four-momentum transfer squared (−t) dependence of the flavor nonsinglet (u−d) H and E GPDs.

关键词： Generalized parton distributions Lattice QCD Lattice field theory Lattice gauge theory Non-Abelian gauge theories parton distribution functions QCD phenomenology Quantum chromodynamics Strong interaction

来源：评论

学校读者我要写书评

暂无评论

ResBos and ePump Analysis on ATLAS 8TeV Z Boson Transverse Momentum distributions

引用

INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS 2021年第8期60卷 3013-3023页

作者： Jandaolet, Qaynar Ablat, Alim Obul, Pazilet Rashidin, Reyima Sitiwaldi, Ibrahim Xinjiang Univ Sch Phys Sci & Technol Urumqi 830046 Xinjiang Peoples R China

Fixed-order predictions cannot describe the vector boson production process in low transverse momentum regions where resummation of soft gluon emission is essential. Using a ResBos Monte Carlo package, we perform the resummed theoretical predictions for the transverse momentum distributions of Z boson measured in proton-proton collision at root s= 8TeV with ATLAS detector at LHC. We compare our results with data and fixed-order NNLO predictions. We find that the ResBos predictions significantly improve the agreement between the data and theory until the transverse momentum of the boson exceeds its invariant mass. However, in the high transverse momentum region, ResBos predictions approximate to fixed-order NNLO calculations and cannot describe well the data, the deviation between data and theory can be covered by the scale uncertainty. In addition, we study the impact of absolute and normalized ATLAS 8TeV Z boson transverse momentum distributions on CT18NNLO PDFs considering the low transverse momentum region where the ResBos predictions are reliable. We find that the traverse momentum distributions in the mass region 66 GeV < M-u < 116 GeV have a significant impact on CT18NNLO PDFs, benefiting from the high precision of the data. Furthermore, we demonstrate that absolute and normalized distributions have approximately the same impact on the PDFs.

关键词： QCD Resummation LHC Transverse momentum Vector boson parton distribution functions

来源：评论

学校读者我要写书评

暂无评论

Nucleon form factors and parton distributions in nonlocal chiral effective theory

引用

PROGRESS IN PARTICLE AND NUCLEAR PHYSICS 2023年 129卷

作者： Wang, P. He, Fangcheng Ji, Chueng-Ryong Melnitchouk, W. Chinese Acad Sci Inst High Energy Phys POB 918 4 Beijing 100049 Peoples R China Univ Chinese Acad Sci Coll Phys Sci Beijing 100049 Peoples R China Chinese Acad Sci Inst Theoret Phys Key Lab Theoret Phys Beijing 100190 Peoples R China North Carolina State Univ Dept Phys Raleigh NC 27695 USA Jefferson Lab Newport News VA 23606 USA

We present a review of recent applications of nonlocal chiral effective theory to hadron structure studies. Starting from a nonlocal meson-baryon effective chiral Lagrangian, we show how the introduction of a correlation function representing the finite extent of hadrons regularizes the meson loop integrals and introduces momentum dependence in vertex form factors in a gauge invariant manner. We apply the framework to the calculation of nucleon electromagnetic form factors, unpolarized and polarized parton distributions, as well as transverse momentum dependent distributions and generalized parton distributions.

关键词： Nucleon form factors parton distribution functions Chiral effective theory Nonlocal Lagrangian GPDs

来源：评论

学校读者我要写书评

暂无评论

Extraction of transhelicity worm-gear distributions and opportunities at the Electron-Ion Collider in China

引用

Physical Review D 2024年第3期110卷 034036页

作者： Ke Yang Tianbo Liu Peng Sun Yuxiang Zhao Bo-Qiang Ma School of Physics Key Laboratory of Particle Physics and Particle Irradiation (MOE) Institute of Frontier and Interdisciplinary Science Southern Center for Nuclear-Science Theory (SCNT) Chinese Academy of Sciences Lanzhou Gansu Province 730000 China Beijing 100049 China Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics Center for High Energy Physics Beijing China

We present a global analysis of the transhelicity worm-gear distribution function, g1T⊥, by fitting the longitudinal-transverse double-spin asymmetry data of the semi-inclusive deep inelastic scattering. The analysis is performed within the framework of transverse momentum dependent factorization and evolution. It is found that the u-quark favors a positive distribution and the d-quark favors a negative distribution, which is consistent with previous model calculations and phenomenological extractions. Based on the fit to existing world data, we also study the impact of the proposed Electron-Ion Collider in China and conclude that it can significantly improve the precision of the worm-gear distribution function and hence enhance our understanding of nucleon spin structures.

关键词： Deep inelastic scattering parton distribution functions Spin-dependent parton distribution functions Transverse momentum dependent distribution Nucleon spin structure

来源：评论

学校读者我要写书评

暂无评论

QCD analysis of valence structure functions using deep inelastic lepton-nucleon scattering

引用

Physical Review D 2024年第11期109卷 114002-114002页

作者： Javad Shahrzad Ali Khorramian Faculty of Physics Semnan University P.O. Box 35131-19111 Semnan Iran

A new “SK24” nonsinglet QCD analysis of the structure functions at the NNLO approximation is performed, utilizing the global fit of the data from various charged lepton scattering experiments. We extract the valence parton distribution functions (PDFs) and provide a parametrization of them, along with the correlated errors for a wide range of x and Q2. We compare valence PDFs and their uncertainties with those from different PDF sets provided by various groups. We also obtain valence PDFs and the strong coupling constant αs(MZ2), taking into account the nuclear correction concerning large x as well as the target mass correction (TMC) and higher twist (HT) effects at the NNLO. In the large x region, we extract the higher twist contributions of xF3(x,Q2), F2p(x,Q2), and F2d(x,Q2). We determine αs(MZ2) without and with considering the TMC and HT corrections and perform a comparison with the world average of αs(MZ2) and other reported results. The extracted results concerning valence PDFs with their uncertainties and αs(MZ2) value agree with available theoretical models.

关键词： parton distribution functions Perturbative QCD Quark model Strong interaction

来源：评论

学校读者我要写书评

暂无评论

Analysis of parton distributions in a pion with Bézier parametrizations

引用

Physical Review D 2024年第7期109卷 074027-074027页

作者： Lucas Kotz Aurore Courtoy Pavel Nadolsky Fredrick Olness Maximiliano Ponce-Chavez Department of Physics Southern Methodist University Dallas Texas 75275-0175 USA Instituto de Física Universidad Nacional Autónoma de México Apartado Postal 20-364 01000 Ciudad de México Mexico

We explore the role of parametrizations for nonperturbative QCD functions in global analyses, with a specific application to extending a phenomenological analysis of the parton distribution functions (PDFs) in the charged pion realized in the xFitter fitting framework. The parametrization dependence of PDFs in our pion fits substantially enlarges the uncertainties from the experimental sources estimated in the previous analyses. We systematically explore the parametrization dependence by employing a novel technique to automate generation of polynomial parametrizations for PDFs that makes use of Bézier curves. This technique is implemented in a c++ module fantômas that is included in the xFitter program. Our analysis reveals that the sea and gluon distributions in the pion are not well disentangled, even when considering measurements in leading-neutron deep inelastic scattering. For example, the pion PDF solutions with a vanishing gluon and large quark sea are still experimentally allowed, which elevates the importance of ongoing lattice and nonperturbative QCD calculations, together with the planned pion scattering experiments, for conclusive studies of the pion structure.

关键词： parton distribution functions Perturbative QCD QCD phenomenology Quantum chromodynamics Pions Data analysis

来源：评论

学校读者我要写书评

暂无评论

Spatial resolution of dijet photoproduction in near-encounter ultraperipheral nuclear collisions

引用

Physical Review C 2024年第5期110卷 054906-054906页

作者： Kari J. Eskola Vadim Guzey Ilkka Helenius Petja Paakkinen Hannu Paukkunen University of Jyväskylä Department of Physics P.O. Box 35 FI-40014 University of Jyväskylä Finland and Helsinki Institute of Physics P.O. Box 64 FI-00014 University of Helsinki Finland

We present next-to-leading order perturbative QCD predictions for inclusive dijet photoproduction in ultraperipheral nucleus-nucleus collisions (UPCs) within the impact-parameter dependent equivalent photon approximation. Taking into account the finite size of both the photon-emitting nucleus and the target nucleus, we show that this process is sensitive to the transverse-plane geometry of the UPC events. We show that this leads to a sizable, 20–40% effect for large values of the zγ variable in the dijet photoproduction cross section in lead-lead UPCs at 5.02 TeV compared to the widely used pointlike approximation where the nuclear radius is accounted for only as a sharp cutoff in the photon flux calculation. This resolution of the spatial degrees of freedom is a result of having high-transverse-momentum jets in the final state, which at the large-zγ kinematics requires a highly energetic photon in the initial state, thus biasing the collisions to small impact-parameter “near-encounter” configurations. We further discuss the role of the forward-neutron event-class selection in isolating the photonuclear cross section in the nucleus-nucleus collisions, and employ the needed electromagnetic breakup survival factor in our predictions.

关键词： Generalized parton distributions Nuclear charge distribution Nucleon distribution parton distribution functions Perturbative QCD Photonuclear reactions Quark & gluon jets Relativistic heavy-ion collisions

来源：评论

学校读者我要写书评

暂无评论

Unifying the landscape of nucleon structure: An infrared-safe evolution scheme

引用

Physical Review D 2024年第11期110卷 114011-114011页

作者： Rong Wang Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China and School of Nuclear Science and Technology University of Chinese Academy of Sciences Beijing 100049 China

A novel approach for describing the evolution of nucleon structure from low-Q2 regime to high-Q2 asymptotic region is proposed. This infrared-safe scheme modifies the parton distribution evolution equations to incorporate the corrections from emergent hadron mass mechanisms and parton-parton recombination at low Q2. The effective quark mass, generated by dynamical chiral symmetry breaking, slows the evolution of parton distributions in the infrared region, causing the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution to freeze when Q2≪Mq/g. Notably, this scheme renders the high-Q2 parton distributions insensitive to the choice of input hadronic scale. The parton-parton recombination effect is crucial in suppressing the rapid growth of parton distributions at small x, consistent with experimental data. When applied to three valence quark distributions derived from a quark model, our scheme yields parton distributions that agree well with deep-inelastic scattering data in both large-x and small-x regions, providing a unified description of nucleon structure across the entire Q2 range.

关键词： parton distribution functions Quantum chromodynamics Quark model Schwinger-Dyson equations Hadrons Quarks

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：