检索结果-内蒙古大学图书馆

ManeParse: A Mathematica reader for parton distribution functions

COMPUTER PHYSICS COMMUNICATIONS 2017年 216卷 126-137页

作者： Clark, D. B. Godat, E. Olness, F. I. Southern Methodist Univ Dept Phys Dallas TX 75275 USA

parton distribution functions (PDFs) are essential non-perturbative inputs for calculation of any observable with hadronic initial states. These PDFs are released by individual groups as discrete grids as a function of the Bjorken-x and energy scale Q. The LHAPDF project maintains a repository of PDFs from various groups in a new standardized LHAPDF6 format, additionally older formats such as the CTEQ PDS grid format are still in use. ManeParse is a package that provides access to PDFs within Mathematica to facilitate calculation and plotting. The program is self-contained so there are no external links to any FORTRAN, C or C++ programs. The package includes the option to use the built-in Mathematica interpolation or a custom cubic Lagrange interpolation routine which allows for flexibility in the extrapolation (particularly at small x-values). ManeParse is fast enough to enable simple calculations (involving even one or two integrations) in the Mathematica framework. Program summary Program Title: ManeParse Program Files doi: http://***10.17632/knbsccggg4.1 Licensing provisions: MIT Programming language: Mathematica Nature of problem: PDFs are currently read and interpolated via a FORTRAN or C++ interface. No method exist to read the LHAPDF6 or CTEQ PDFs directly in Mathematica. Solution method: A Mathematica package reads in LHAPDF6 and CTEQ PDF files. The PDFs are parsed into a three-dimensional array in Bjorken-x, scattering energy Q, and parton flavor, and are stored in memory. Provided functions give access to the PDF, the PDF uncertainty, the PDF correlations, and the parton-parton Luminosities. The LHAPDF6 info files are converted from YAML format into Mathematica rules. (C) 2017 Elsevier B.V. All rights reserved.

关键词： QCD Mathematica parton distribution functions PDF PDFs Hadron collider PDF errors Hadronic cross section

来源：评论

学校读者我要写书评

暂无评论

Impact of the top quark cross-section data on parton distribution functions

引用

INTERNATIONAL JOURNAL OF MODERN PHYSICS A 2018年第24期33卷

作者： Azizi, M. Khorramian, A. Abdolmaleki, H. Semnan Univ Fac Phys POB 35195-363 Semnan Iran

Recent measurements of top quark pair production cross-section, which is performed at the LHC and the Tevatron collider, are studied using Hessian profiling technique to obtain their impact on the parton distribution functions (PDFs). The top quark production data covers different center-of-mass energies root s = 1.96, 5.02, 7, 8 and 13 TeV in either pp or p (p) over bar collisions. It is explained how the Hessian profiling method may be used to assess the impact of these new data on PDFs and consequently on their predictions. In this research, the impact of recent measurements of top quark pair cross-sections on different CT14, MMHT2014 and NNPDF3.0 PDF sets is investigated. The analysis results show that the recent top quark production at the LHC and Tevatron data provide significant constraints in particular on the central value, relative uncertainties or both for the s-quark distribution and the gluon PDFs in both CT14 and MMHT2014 PDF sets and are insensitive to valence-quark PDFs. A small constraint on the (u) over bar -sea quark distribution for CT14 PDF is also observed. There is no impact on the NNPDF3.0 PDF set in presence of these data.

关键词： QCD parton distribution functions top quark production profiling method

来源：评论

学校读者我要写书评

暂无评论

Quark shapes of most modern parton distribution functions

引用

TURKISH JOURNAL OF PHYSICS 2017年第6期41卷 545-550页

作者： Ogul, Hasan Sinop Univ Dept Nucl Engn Fac Engn & Architecture Sinop Turkey

parton distribution functions (PDFs) describe the internal structure of the proton and are necessary inputs to almost all theory predictions of hadron colliders. One way to do a precise measurement of a PDF is to measure the lepton charge asymmetry of W boson where u (d) over bar -> W+ and d (u) over bar -> W-. Therefore, u, d, (u) over bar, and (d) over bar quark shapes of the most modern PDF models (NNPDF3.1, NNPDF3.0, CT14, MMHT2014, and HERAPDF2.0) are inspected using the APFEL online cluster in this paper. The ratio of d to u is further investigated since the charge asymmetry is sensitive to the value of d over u momentum distributions in the proton. Q scale dependence of PDFs are further studied in a range from 1 to 100 GeV.

关键词： High energy physics parton distribution functions NNPDF3.1 quarks

来源：评论

学校读者我要写书评

暂无评论

Estimating Quantum Statistical parton distribution functions in proton by maximum entropy method

引用

INTERNATIONAL JOURNAL OF MODERN PHYSICS A 2018年第30期33卷

作者： Sohaily, Sozha Shahid Bahonar Univ Kerman Fac Phys Kerman Iran

An attempt to extend simple parton distribution functions based on the quantum statistical model to consider more active flavors is presented here. Considering partons as clusters, inspiring from the static picture of proton composed of three valence quarks, such a reasonable extension is surveyed to improve the results. Analytic expressions for the longitudinal Quantum Statistical parton distribution functions are obtained by applying the maximum entropy principle beside theoretical proton sum rules. Furthermore, the main purpose of this study is to predict a minimum energy scale to probe the proton with a defined condition, theoretically. An interesting approach to determine the statistical variables exactly without fitting and fixing is employed and the consistency of computed distributions with the experimental observations gives a robust confirm of presented simple statistical model.

关键词： Quantum statistical model parton distribution functions nucleon structure entropy

来源：评论

学校读者我要写书评

暂无评论

The impact of CMS inclusive jet data on parton distribution functions and their uncertainties

引用

INTERNATIONAL JOURNAL OF MODERN PHYSICS A 2017年第22期32卷

作者： Aleedaneshvar, A. Khorramian, A. Semnan Univ Fac Phys POB 35195-363 Semnan Iran

It is well known that the jet production data at LHC provide important constraints on the medium and large-x gluon parton distribution function (PDF), as well as on the large-x sea quarks. In this work, we study the impact of recent CMS measurements for the inclusive jet production at center-of-mass energy of root s = 13 TeV on the PDFs and their uncertainties. To this aim, with use of the FastNLO and xFitter framework, we apply the parton distribution re-weighting procedure to study the impact of CMS data on two NLO modern CT14 and MMHT PDF sets. As a result, we found that the fit quality obtained using both of these PDF sets is very good. Moreover, the CMS data can impact both the central values and uncertainties of some PDFs especially at low and large x regions. Overall, it is indicated that the CT14 PDFs compared with the MMHT ones are more affected. We emphasis that the inclusion of these data in a new global analysis of PDFs can improve the determination of the gluon and quark PDFs at both low and large x regions.

关键词： parton distribution functions inclusive jet LHC

来源：评论

学校读者我要写书评

暂无评论

Color Entanglement in Hadronic Processes for Transverse Momentum Dependent parton distribution functions

引用

International Journal of Modern Physics: Conference Series 2015年第37期ijmpcs卷

作者： M. G. A. Buffing P. J. Mulders Theory Group Nikhef & Department of Physics Faculty of Science VU University De Boelelaan 1081 NL-1081 HV Amsterdam The Netherlands

In the description of protons, we go beyond the ordinary collinear parton distribution functions (PDFs), by including transverse momentum dependent PDFs (TMDs). As such, we become sensitive to polarization modes of the partons and protons that one cannot probe without accounting for transverse momenta of partons, in particular when looking at azimuthal asymmetries. Hadronic processes require the inclusion of gluon contributions forming the gauge links, which are path-ordered exponentials tracing the color flow. In processes with two hadrons in the initial state, such as Drell-Yan (DY), the gauge links from different parts of the process get entangled. We show that in color disentangling this gauge link structure, one becomes sensitive to this color flow. After disentanglement, particular combinations of TMDs will require a different numerical color factor than one naively might have expected. Such color factors will even play a role for azimuthal asymmetries in the simplest hadronic processes such as DY.

关键词： Drell-Yan parton distribution functions gauge links

来源：评论

学校读者我要写书评

暂无评论

A MODEL CONSTRUCTION OF SELF-SIMILARITY BASED DOUBLE parton distribution functions FOR PROTON-PROTON COLLISION AT LHC

引用

INTERNATIONAL JOURNAL OF MODERN PHYSICS A 2013年第17期28卷 13500796-1-13500796-13页

作者： Choudhury, D. K. Jahan, Akbari Gauhati Univ Dept Phys Gauhati 781014 Assam India

We construct a model for double parton distribution functions (dPDFs) based on the notion of self-similarity, pursued earlier for small x physics at HERA. The most general form of dPDFs contains total 13 parameters to be fitted from data of proton-proton collision at LHC. It is shown that the constructed dPDF does not factorize into two single PDFs in conformity with QCD expectation, and it satisfies the condition that at the kinematic boundary x(1) + x(2) = 1 (where x(1) and x(2) are the longitudinal fractional momenta of two partons), the dPDF vanishes.

关键词： Self-similarity parton distribution functions small x

来源：评论

学校读者我要写书评

暂无评论

Spectroscopy of excited quarkonium states in the light-front quark model

引用

Chinese Physics C 2025年第2期49卷 33-46页

作者： Ritwik Acharyya Satyajit Puhan Harleen Dahiya Narinder Kumar Computational High Energy Physics Lab Department of PhysicsDr.B R Ambedkar National Institute of Technology JalandharPunjabIndia144008 Computational Theoretical High Energy Physics Lab Department of PhysicsDoaba CollegeJalandhar 144004India

We investigated the ground state(1S),radially excited states(2S)and(3S),and orbitally excited state(1P)for the heavy charmonia(cc)and bottomonia(bb)mesons in the light-front quark model(LFQM).The light-front wave functions have been successful in explaining various physical properties of meson states in the past,especially for the 1S and 2S ***,the radially excited state 3S and orbitally excited state 1P have rarely been *** this study,we considered these two excited states and investigated the electromagnetic form factors(EMFFs),charge radii,decay constants,parton distribution functions(PDFs),and the distribution amplitudes(DAs)for the quarkonia *** the sake of completeness,we also studied the ground and the first excited states of quarkonia *** also illustrated the 3D wave functions for the radially excited states to study their nodal structures.

关键词： decay constants distribution amplitudes form factors parton distribution functions light-front quark model heavy charmonia and bottomonia

来源：评论

学校读者我要写书评

暂无评论

Hyperparameter optimisation in deep learning from ensemble methods: applications to proton structure

引用

MACHINE LEARNING-SCIENCE AND TECHNOLOGY 2025年第2期6卷

作者： Cruz-Martinez, Juan Jansen, Aron van Oord, Gijs Rabemananjara, Tanjona R. Rocha, Carlos M. R. Rojo, Juan Stegeman, Roy CERN Theoret Phys Dept CH-1211 Geneva 23 Switzerland Netherlands Esci Ctr Sci Pk 140 NL-1098 XG Amsterdam Netherlands Vrije Univ Dept Phys & Astron NL-1081 HV Amsterdam Netherlands Nikhef Theory Grp Sci Pk 105 NL-1098 XG Amsterdam Netherlands Univ Edinburgh Higgs Ctr Theoret Phys JCMB KB Mayfield Rd Edinburgh EH9 3FD Scotland

Deep learning models are defined in terms of a large number of hyperparameters, such as network architectures and optimiser settings. These hyperparameters must be determined separately from the model parameters such as network weights, and are often fixed by ad-hoc methods or by manual inspection of the results. An algorithmic, objective determination of hyperparameters demands the introduction of dedicated target metrics, different from those adopted for the model training. Here we present a new approach to the automated determination of hyperparameters in deep learning models based on statistical estimators constructed from a ensemble of models sampling the underlying probability distribution in model space. This strategy requires the simultaneous parallel training of up to several hundreds of models and can be effectively implemented by deploying hardware accelerators such as graphical processing units (GPUs). As a proof-of-concept, we apply this method to the determination of the partonic substructure of the proton within the NNPDF framework and demonstrate the robustness of the resultant model uncertainty estimates. The new GPU-optimised NNPDF code results in a speed-up of up to two orders of magnitude, a stabilisation of the memory requirements, and a reduction in energy consumption of up to 90% as compared to sequential CPU-based model training. While focusing on proton structure, our method is fully general and is applicable to any deep learning problem relying on hyperparameter optimisation for an ensemble of models.

关键词： hyperoptimisation machine learning hardware acceleration proton structure parton distribution functions GPU high-energy physics

来源：评论

学校读者我要写书评

暂无评论

Kaon distribution functions from empirical information

引用

PHYSICS LETTERS B 2025年 865卷

作者： Xu, Zhen-Ni Binosi, Daniele Chen, Chen Raya, Khepani Roberts, Craig D. Rodriguez-Quintero, Jose Univ Huelva Dept Integrated Sci E-21071 Huelva Spain Univ Huelva Ctr Adv Studies Phys Math & Computat E-21071 Huelva Spain European Ctr Theoret Studies Nucl Phys & Related A Villa TambosiStr Tabarelle 286 I-38123 Villazzano TN Italy Univ Sci & Technol China USTC Interdisciplinary Ctr Theoret Study Hefei 230026 Anhui Peoples R China Peng Huanwu Ctr Fundamental Theory PCFT Hefei 230026 Anhui Peoples R China Nanjing Univ Sch Phys Nanjing 210093 Jiangsu Peoples R China Nanjing Univ Inst Nonperturbat Phys Nanjing 210093 Jiangsu Peoples R China Univ Paris Saclay Irfu CEA F-91191 Gif Sur Yvette France

Using available information from Drell-Yan data on pion and kaon structure functions, an approach is described which enables the development of pointwise profiles for all pion and kaon parton distribution functions (DFs) without reference to theories of hadron structure. The key steps are construction of structure-function-constrained probability-weighted ensembles of valence DF replicas and use of an evolution scheme for parton DFs that is all-orders exact. The DFs obtained express qualitatively sound features of light-meson structure, e.g., the effects of Higgs boson couplings into QCD and the size of heavy-quark momentum fractions in light hadrons. In order to improve the results, additional and more precise data on the u-quark-in-kaon, uK, to u-quark-in-pion, u pi, DF ratio would be necessary. Of greater value would be extraction of uK alone, thereby avoiding inference from the ratio: currently, the data-based form of uK is materially influenced by results for u pi.

关键词： Continuum Schwinger function methods Drell-Yan reactions Emergence of mass Meson structure functions Nambu-Goldstone bosons parton distribution functions

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：