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相关论文: The NNPDF2.2 Parton Set

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Ensemble methods are among the state-of-the-art predictive modeling approaches. Applied to modern big data, these methods often require a large number of sub-learners, where the complexity of each learner typically grows with the size of…

机器学习 · 计算机科学 2018-10-29 Amichai Painsky , Saharon Rosset

Understanding nuclear effects in parton distribution functions (PDF) is an essential component needed to determine the strange and anti-strange quark contributions in the proton. In addition Nuclear Parton Distribution Functions (NPDF) are…

高能物理 - 唯象学 · 物理学 2010-11-19 Karol Kovarik

Parton distribution functions (PDFs) describe universal properties of bound states and allow us to calculate scattering amplitudes in processes with large momentum transfer. Calculating PDFs involves the evaluation of matrix elements with a…

高能物理 - 格点 · 物理学 2025-02-10 Mari Carmen Bañuls , Krzysztof Cichy , C. -J. David Lin , Manuel Schneider

We present an extended version of the \texttt{ePump} framework that enables the simultaneous profiling of proton parton distribution functions (PDFs) and the strong coupling $\alpha_s$ using new experimental data. By promoting $\alpha_s$ to…

高能物理 - 唯象学 · 物理学 2026-03-24 Yao Fu , Carl Schmidt , C. --P. Yuan

Parton distribution functions (PDFs) are nonperturbative objects defined by nonlocal light-cone correlations. They cannot be computed directly from Quantum Chromodynamics (QCD). Using a standard lattice QCD approach, it is possible to…

高能物理 - 唯象学 · 物理学 2017-02-08 Alessandro Bacchetta , Marco Radici , Barbara Pasquini , Xiaonu Xiong

We discuss a test of the generalization power of the methodology used in the determination of parton distribution functions (PDFs). The "future test" checks whether the uncertainty on PDFs, in regions in which they are not constrained by…

高能物理 - 唯象学 · 物理学 2021-04-21 Juan Cruz-Martinez , Stefano Forte , Emanuele R. Nocera

We perform a next-to-next-to-leading order (NNLO) analysis of nuclear parton distribution functions (nPDFs) using neutral current charged-lepton ($\ell ^\pm$ + nucleus) deeply inelastic scattering (DIS) data and Drell-Yan (DY) cross-section…

高能物理 - 唯象学 · 物理学 2016-01-29 Hamzeh Khanpour , S. Atashbar Tehrani

Ensemble learning is a mainstay in modern data science practice. Conventional ensemble algorithms assign to base models a set of deterministic, constant model weights that (1) do not fully account for individual models' varying accuracy…

统计方法学 · 统计学 2019-04-02 Jeremiah Zhe Liu , John Paisley , Marianthi-Anna Kioumourtzoglou , Brent A. Coull

As both predictions and measurements of high-energy physics observables become more precise, controlling all sources of uncertainties in determinations of parton distribution functions (PDFs) becomes increasingly important. One source of…

高能物理 - 唯象学 · 物理学 2022-12-16 Roy Stegeman

We critically assess the robustness of uncertainties on parton distribution functions (PDFs) determined using neural networks from global sets of experimental data collected from multiple experiments. We view the determination of PDFs as an…

高能物理 - 唯象学 · 物理学 2025-03-25 Andrea Barontini , Mark N. Costantini , Giovanni De Crescenzo , Stefano Forte , Maria Ubiali

We review recent progress towards a determination of a set of polarized parton distributions from a global set of deep-inelastic scattering data based on the NNPDF methodology, in analogy with the unpolarized case. This method is designed…

高能物理 - 唯象学 · 物理学 2010-11-19 J. Rojo , G. Ridolfi , R. D. Ball , V. Bertone , F. Cerutti , L. Del Debbio , S. Forte , A. Guffanti , J. I. Latorre , M. Ubiali

The parton distributions functions (PDFs) derived from the NNLO QCD analysis of existing light-targets deep-inelastic-scattering data are presented. The NLO and NNLO PDFs are compared in order to analyze perturbative stability of the…

高能物理 - 唯象学 · 物理学 2007-05-23 S. Alekhin

We extract pion parton distribution functions (PDFs) in a Monte Carlo global QCD analysis of experimental data together with reduced Ioffe time pseudo-distributions and matrix elements of current-current correlators generated from lattice…

高能物理 - 唯象学 · 物理学 2022-07-13 P. C. Barry , C. Egerer , J. Karpie , W. Melnitchouk , C. Monahan , K. Orginos , Jian-Wei Qiu , D. Richards , N. Sato , R. S. Sufian , S. Zafeiropoulos

We implement a Monte Carlo sampling strategy to extract helicity parton densities and their uncertainties from a reference set of longitudinally polarized scattering data, chosen to be that used in the DSSV14 global analysis. Instead of…

高能物理 - 唯象学 · 物理学 2019-12-25 Daniel de Florian , Gonzalo Agustin Lucero , Rodolfo Sassot , Marco Stratmann , Werner Vogelsang

We perform a global QCD analysis of unpolarized parton distributions within a Bayesian Monte Carlo framework, including the new $W$-lepton production data from the STAR Collaboration at RHIC and Drell-Yan di-muon data from the SeaQuest…

高能物理 - 唯象学 · 物理学 2021-10-29 C. Cocuzza , W. Melnitchouk , A. Metz , N. Sato

Parton distribution function (PDF) at small $x$ in a fast-moving proton is investigated within an upgraded parton model that includes parton splitting with branching cascades and parton fusion. In the region of moderately small $x$, we…

高能物理 - 唯象学 · 物理学 2026-02-27 M. L. Nekrasov

This paper investigates the crucial role of parton distribution functions (PDFs) in high-energy physics, particularly their impact on the extraction of generalized parton distributions (GPDs) at zero skewness. To this aim, we perform six…

高能物理 - 唯象学 · 物理学 2026-03-23 The MMGPDs Collaboration , Fatemeh Irani , Muhammad Goharipour , K. Azizi

We perform the first global QCD analysis of parton distribution functions (PDFs) in the pion, combining $\pi A$ Drell-Yan data with leading neutron electroproduction from HERA within a Monte Carlo approach based on nested sampling.…

高能物理 - 唯象学 · 物理学 2018-10-17 P. C. Barry , N. Sato , W. Melnitchouk , Chueng-Ryong Ji

A Bayesian framework is attractive in the context of prediction, but a fast recursive update of the predictive distribution has apparently been out of reach, in part because Monte Carlo methods are generally used to compute the predictive.…

统计方法学 · 统计学 2018-12-11 P. Richard Hahn , Ryan Martin , Stephen G. Walker

We review the theoretical foundations, methodological approaches and current status of the determination of nuclear parton distribution functions (PDFs). A large variety of measurements in fixed-target and collider experiments provide…

高能物理 - 唯象学 · 物理学 2024-07-16 M. Klasen