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We present the first global analysis of parton distribution functions (PDFs) at approximate N$^{3}$LO in the strong coupling constant $\alpha_{s}$, extending beyond the current highest NNLO achieved in PDF fits. To achieve this, we present…

High Energy Physics - Phenomenology · Physics 2023-03-14 J. McGowan , T. Cridge , L. A. Harland-Lang , R. S. Thorne

The analysis and the interpretation of the LHC data require a precise determination of Parton Distribution Functions (PDFs) in order to detect reliably potential signs of new physics. I present a systematic study designed to assess the risk…

High Energy Physics - Phenomenology · Physics 2023-10-17 Elie Hammou

The interpretation of LHC measurements requires a careful estimate of various sources of uncertainties that affect theoretical calculations. In this contribution, we present the PDF4LHC Working Group recommendations for the usage of sets of…

High Energy Physics - Phenomenology · Physics 2016-06-28 Juan Rojo

We present the software framework underlying the NNPDF4.0 global determination of parton distribution functions (PDFs). The code is released under an open source licence and is accompanied by extensive documentation and examples. The code…

Pearson's chi-squared test is widely used to test the goodness of fit between categorical data and a given discrete distribution function. When the number of sets of the categorical data, say $k$, is a fixed integer, Pearson's chi-squared…

Methodology · Statistics 2022-01-03 Shuhua Chang , Deli Li , Yongcheng Qi

We present a new global determination of the helicity-dependent parton distribution functions (PDFs) of the proton, based on inclusive deep-inelastic scattering (DIS) and semi-inclusive DIS (SIDIS) data within a consistent next-to-leading…

High Energy Physics - Phenomenology · Physics 2026-02-20 Hamzeh Khanpour , Maryam Soleymaninia , Majid Azizi , Michael Klasen , Hadi Hashamipour , Maral Salajegheh , Ulf-G. Meißner

We discuss the sensitivity of theoretical predictions of observables used in searches for new physics to parton distributions (PDFs) at large momentum fraction $x$. Specifically, we consider the neutral-current Drell-Yan production of gauge…

High Energy Physics - Phenomenology · Physics 2023-01-18 Richard D. Ball , Alessandro Candido , Stefano Forte , Felix Hekhorn , Emanuele R. Nocera , Juan Rojo , Christopher Schwan

In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing the approach of parton pseudo-distribution functions. We perform a systematic analysis using three lattice ensembles at two…

High Energy Physics - Lattice · Physics 2020-01-29 Bálint Joó , Joseph Karpie , Kostas Orginos , Anatoly Radyushkin , David Richards , Savvas Zafeiropoulos

We present the new MSHT20 set of parton distribution functions (PDFs) of the proton, determined from global analyses of the available hard scattering data. The PDFs are made available at NNLO, NLO, and LO, and supersede the MMHT14 sets.…

High Energy Physics - Phenomenology · Physics 2022-08-22 S. Bailey , T. Cridge , L. A. Harland-Lang , A. D. Martin , R. S. Thorne

Experimental data in particle and nuclear physics, particle astrophysics, and radiation protection dosimetry are collected using experimental facilities that consist of a complex system of sensors, electronics, and software. Measured…

Data Analysis, Statistics and Probability · Physics 2026-03-04 Nikolay D. Gagunashvili

In this paper, we develop an approach to calculate the valence-quark quasi parton distribution amplitude (quasi-PDA) and quasi parton distribution function (quasi-PDF) for the pion with a large longitudinal momentum with the functional…

High Energy Physics - Phenomenology · Physics 2025-02-24 Dao-yu Zhang , Chuang Huang , Wei-jie Fu

For testing goodness of fit it is very popular to use either the chi square statistic or G statistics (information divergence). Asymptotically both are chi square distributed so an obvious question is which of the two statistics that has a…

Statistics Theory · Mathematics 2012-06-19 Peter Harremoës , Gábor Tusnády

This paper presents a new method to estimate systematic errors in the maximum-likelihood regression of count data. The method is applicable in particular to X-ray spectra in situations where the Poisson log-likelihood, or the Cash…

Instrumentation and Methods for Astrophysics · Physics 2023-05-03 M. Bonamente

We derive the sampling probability density function (pdf) of an ideal localized random electromagnetic field, its amplitude and intensity in an electromagnetic environment that is quasi-statically time-varying statistically homogeneous or…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 L. R. Arnaut

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…

High Energy Physics - Phenomenology · Physics 2024-04-17 Lucas Kotz , Aurore Courtoy , Pavel Nadolsky , Fredrick Olness , Maximiliano Ponce-Chavez

Uncertainties on parton distribution functions (PDFs) compromise discovery at the LHC for any new physics which can be described as a contact-interaction. PDF uncertainties also limit our ability to use W and Z cross-sections as an accurate…

High Energy Physics - Phenomenology · Physics 2007-07-12 A M Cooper-Sarkar

The full exploitation of the increasingly precise LHC measurements is essential in order to reduce the uncertainty of theoretical predictions at hadron colliders. The NNPDF2.3 fit was the first PDF determination including the effect of the…

High Energy Physics - Phenomenology · Physics 2014-07-14 Maria Ubiali

Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear…

High Energy Physics - Phenomenology · Physics 2014-11-20 Paloma Quiroga-Arias , Jose Guilherme Milhano , Urs Achin Wiedemann

We have presented the results of our next-to-next-to-leading order (NNLO) QCD analysis of nuclear parton distribution functions (nuclear PDFs) [Phys. Rev. D 93 (2016) 014026, arXiv:1601.00939 [hep-ph]] using all available neutral current…

High Energy Physics - Phenomenology · Physics 2020-12-17 S. Atashbar Tehrani

Statistical divergences are ubiquitous in machine learning as tools for measuring discrepancy between probability distributions. As these applications inherently rely on approximating distributions from samples, we consider empirical…

Statistics Theory · Mathematics 2020-05-01 Ziv Goldfeld , Kengo Kato