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Related papers: Quasi-parton distribution functions: a study in th…

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We discuss the recent progress in extracting partonic functions from the quasi-distribution approach, using twisted mass fermions. This concerns, among others, the investigation of several sources of systematic effects. Their careful…

Parton distribution functions (PDFs) at large $x$ are poorly constrained by high-energy experimental data, but extremely important for probing physics beyond standard model at colliders. We study the calculation of PDFs at large-$x$ through…

High Energy Physics - Phenomenology · Physics 2025-08-05 Xiangdong Ji , Yizhuang Liu , Yushan Su

The pseudo- and the quasi-PDFs defined through space-like separated bilocal operators allow direct access to the parton distribution functions (PDFs) from first principles within lattice gauge theory. This formalism, however, leaves the…

High Energy Physics - Phenomenology · Physics 2023-05-04 Giovanni Antonio Chirilli

The quasi-PDF approach provides a path to computing parton distribution functions (PDFs) using lattice QCD. This approach requires matrix elements of a power-divergent operator in a nucleon at high momentum and one generically expects…

We show the first results for parton distribution functions within the proton at the physical pion mass, employing the method of quasi-distributions. In particular, we present the matrix elements for the iso-vector combination of the…

We propose a modified definition for a quasi-parton distribution function (QPDF) with an equal-time correlator in the large momentum limit, whose two pieces of space-like Wilson links are oriented in orthogonal directions. It is explicitly…

High Energy Physics - Phenomenology · Physics 2016-11-02 Hsiang-nan Li

We present a next-to-next-to-leading order (NNLO) calculation of the quasi parton distribution functions (Quasi-PDFs) in the large momentum effective theory (LaMET). We focus on the flavor non-diagonal quark-quark channel and demonstrate…

High Energy Physics - Phenomenology · Physics 2020-08-05 Long-Bin Chen , Wei Wang , Ruilin Zhu

The one loop matching kernels between parton distribution functions (PDFs) for parton $i=u,d,s,g$ and their corresponding quasi-PDFs are computed at one loop in the hybrid-ratio scheme. We found that, in addition to the conservation of the…

High Energy Physics - Lattice · Physics 2025-05-20 Yi-Xian Chen , Jiunn-Wei Chen

We present a detailed study of the helicity-dependent and helicity-independent collinear parton distribution functions (PDFs) of the nucleon, using the quasi-PDF approach. The lattice QCD computation is performed employing twisted mass…

We present a lattice quantum chromodynamics calculation of the $x$-dependent isovector quark helicity parton distribution function (PDF) of the proton in the large momentum effective theory (LaMET) framework. Through operator product…

High Energy Physics - Lattice · Physics 2026-04-06 Xiang Gao , Andrew D. Hanlon , Swagato Mukherjee , Peter Petreczky , Hai-Tao Shu , Fei Yao , Rui Zhang , Yong Zhao

Parton distribution functions (PDFs) at large $x$ are challenging to extract from experimental data, yet they are essential for understanding hadron structure and searching for new physics beyond the Standard Model. Within the framework of…

High Energy Physics - Phenomenology · Physics 2025-03-03 Xiangdong Ji , Yizhuang Liu , Yushan Su , Rui Zhang

Algebraic Ansaetze for the Poincar\'e-covariant Bethe-Salpeter wave functions of the pion and kaon are used to calculate their light-front wave functions (LFWFs), parton distribution amplitudes (PDAs), quasi-PDAs (qPDAs), valence parton…

Nuclear Theory · Physics 2018-05-23 Shu-Sheng Xu , Lei Chang , Craig D. Roberts , Hong-Shi Zong

We compute the leading-twist T-odd quasi-distributions of the proton in a spectator model with scalar and axial-vector diquarks: the quasi Sivers function $\tilde{f}_{1T}^\perp(x, k_T^2; P_z)$ and the quasi Boer-Mulders function…

High Energy Physics - Phenomenology · Physics 2022-11-23 Chentao Tan , Zhun Lu

We present the next-to-next-to-leading order (NNLO) calculation of quark quasi parton distribution functions (PDFs) in the large momentum effective theory. The nontrivial factorization at this order is established explicitly and the full…

High Energy Physics - Phenomenology · Physics 2021-02-24 Long-Bin Chen , Wei Wang , Ruilin Zhu

Even since the "quasi" parton distribution function (PDF) was proposed under the large-momentum effective theory (LaMET) framework, its renormalization under the lattice regularization has been a central challenge to be solved due to the…

High Energy Physics - Lattice · Physics 2019-12-17 Yikai Huo , Peng Sun

We discuss the current developments by the European Twisted Mass Collaboration in extracting parton distribution functions from the quasi-PDF approach. We concentrate on the non-perturbative renormalization prescription recently developed…

In the framework of quantum chromodynamics (QCD), parton distribution functions (PDFs) quantify how the momentum and spin of a hadron are divided among its quark and gluon constituents. Two main approaches exist to determine PDFs. The first…

The recently proposed large momentum effective theory (LaMET) of Ji has led to a burst of activity among lattice practitioners to perform and control the first pioneering calculations of the quasi-PDFs of the nucleon. These calculations…

High Energy Physics - Phenomenology · Physics 2018-03-28 T. J. Hobbs

Within the theory of Quantum Chromodynamics (QCD), the rich structure of hadrons can be quantitatively characterized, among others, using a basis of universal non-perturbative functions: parton distribution functions (PDFs), generalized…

High Energy Physics - Lattice · Physics 2019-06-14 Krzysztof Cichy , Martha Constantinou

We present the first attempt to access the $x$-dependence of the gluon unpolarized parton distribution function (PDF), based on lattice simulations using the large-momentum effective theory (LaMET) approach. The lattice calculation is…

High Energy Physics - Lattice · Physics 2018-12-19 Zhou-You Fan , Yi-Bo Yang , Adam Anthony , Huey-Wen Lin , Keh-Fei Liu