We demonstrate a new method of extracting parton distributions from lattice calculations. The starting idea is to treat the generic equal-time matrix element $\mathcal{M}(P{z}_{3},{z}_{3}^{2})$ as function Ioffe time $\ensuremath{\nu}=P{z}_{3}$ and distance ${z}_{3}$. next step divide by rest-frame density $\mathcal{M}(0,{z}_{3}^{2})$. Our calculation shows linear exponential ${z}_{3}$-dependence in function, expected $Z({z}_{3}^{2})$ factor generated gauge link. Still, we observe that ratio...

We present the first exploratory lattice QCD calculation of pion valence quark distribution extracted from spatially separated current-current correlations in coordinate space. show that an antisymmetric combination vector and axial-vector currents provides direct information on distribution. Using collinear factorization approach, we calculate perturbative tree-level kernel for this current extract The main goal article is to demonstrate efficacy general approach reliable extraction parton...

We present a calculation of the pion valence quark distribution extracted using formalism reduced Ioffe time pseudo-distributions or more commonly known as pseudo-PDFs. Our is carried out on two different 2+1 flavor QCD ensembles isotropic-clover fermion action, with lattice dimensions $24^3\times 64$ and $32^3\times 96$ at spacing $a=0.127$ fm, mass equivalent to $m_\pi \simeq 415$ MeV. incorporate several combinations smeared-point smeared-smeared source-sink interpolation fields in...

The computation of the parton distribution functions (PDF) or amplitudes (DA) hadrons from first principles lattice QCD constitutes a central open problem. In this study, we present and evaluate efficiency selection methods for inverse problems to reconstruct full $x$-dependence PDFs. Our starting point are so called Ioffe time PDFs, which accessible Euclidean calculations in conjunction with matching procedure. Using realistic mock data tests, find that ill-posed incomplete Fourier...

In this paper, we present a detailed study of the unpolarized nucleon parton distribution function (PDF) employing approach pseudo-distribution functions. We perform systematic analysis using three lattice ensembles at two volumes, with spacings $a=$ 0.127 fm and 0.094 fm, for pion mass roughly 400 MeV. With both continuum limit infinite volume extrapolation errors PDF are estimated. addition to $x$ dependence PDF, compute their first moments compare them pertinent phenomenological determinations.

We extract the pion valence quark distribution ${q}_{\mathrm{v}}^{\ensuremath{\pi}}(x)$ from lattice QCD (LQCD) calculated matrix elements of spacelike correlations one vector and axial current analyzed in terms collinear factorization, using a new short-distance matching coefficient to one-loop accuracy. derive Ioffe time two-current physical limit by investigating finite spacing, volume, mass, higher-twist dependencies simultaneous fit computed on four gauge ensembles. find remarkable...

A bstract We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) H u − d ( x , ξ t ) and E in pseudo-distribution formalism using distillation. Taking advantage large kinematic coverage made possible by this approach, we results on moments GPDs up to order 3 — including their skewness dependence at a pion mass m π = 358 MeV lattice spacing 0 . 094 fm.

We present results for the unpolarized parton distribution function of nucleon computed in lattice QCD at physical pion mass. This is first study its kind employing method Ioffe time pseudo-distributions. Beyond reconstruction Bjorken-$x$ dependence we also extract lowest moments using small expansion pseudo-distribution. compare our findings with pertinent phenomenological determinations.

A bstract We examine the relation of moments parton distribution functions to matrix elements non-local operators computed in lattice quantum chromodynamics. argue that after continuum limit is taken, these give access are finite and can be matched those defined $$ \overline{MS} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mrow> <mml:mi>M</mml:mi> <mml:mi>S</mml:mi> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> scheme. demonstrate this fact with a...

A bstract We extract two nonsinglet nucleon Parton Distribution Functions from lattice QCD data for reduced Ioffe-time pseudodistributions. perform such analysis within the NNPDF framework, considering coming different ensembles and dis- cussing in detail treatment of source systematics involved fit. introduce a recipe taking care use it to our extraction light-cone PDFs.

A bstract In this study, we present continuum limit results for the unpolarized parton distribution function of nucleon computed in lattice QCD. This study is first using pseudo-PDF approach with Short Distance Factorization factorizing QCD calculable matrix elements. Our findings are also compared pertinent phenomenological determinations. Inter alia, employing summation Generalized Eigenvalue Problem (sGEVP) technique order to optimize our control over excited state contamination which can...

In this study, we present a determination of the unpolarized gluon Ioffe-time distribution in nucleon from first principles lattice quantum chromodynamics calculation. We carry out calculation on $32^3\times 64$ ensemble with pion mass $358$ MeV and spacing $0.094$ fm. construct interpolating fields using distillation technique, flow gauge gradient flow, solve summed generalized eigenvalue problem to determine glounic matrix elements. Combining these techniques allows us provide...

We present a determination of the non-singlet transversity parton distribution function (PDF) nucleon, normalized with respect to tensor charge at $\mu^2=2$ GeV$^2$ from lattice quantum chromodynamics. apply pseudo-distribution approach, using gauge ensemble spacing 0.094 fm and light quark mass tuned pion 358 MeV. extract PDF analysis short-distance behavior Ioffe-time leading-twist next-to-leading order (NLO) matching coefficients calculated for transversity. reconstruct $x$-dependence...

We present the first exploratory lattice quantum chromodynamics (QCD) calculation of polarized gluon Ioffe-time pseudodistribution in nucleon. The provides a frame-independent and gauge-invariant framework to determine helicity nucleon from principles. employ high-statistics computation using ${32}^{3}\ifmmode\times\else\texttimes\fi{}64$ ensemble characterized by 358 MeV pion mass 0.094 fm spacing. establish approach as feasible method address proton spin puzzle with successive improvements...

We perform a new global analysis of spin-dependent parton distribution functions with the inclusion Ioffe time pseudo-distributions computed in lattice QCD (LQCD), which are directly sensitive to gluon helicity distribution, $Δg$. These data have an analogous relationship distributions as do experimental cross sections, and can be readily included analyses. focus particular on constraining capability current LQCD sign $Δg$ at intermediate momentum fractions $x$, was recently brought into...

Some calculations of parton distributions from first principles only give access to a limited range Fourier modes the function reconstruct. We present physically motivated procedure regularize inverse integral problem using Gaussian process as Bayesian prior. propose fix hyperparameters prior in meaningful physical fashion, offering simple implementation, great numerical efficiency, and allowing us understand keep control easily uncertainty reconstruction. Published by American Physical Society 2025

Extracting parton structure from lattice quantum chromodynamics (QCD) calculations requires studying the coordinate scale <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>z</a:mi><a:mn>3</a:mn></a:msub></a:math> dependence of matrix elements bilocal operators. The most significant contribution comes <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>z</c:mi><c:mn>3</c:mn></c:msub></c:math> induced by ultraviolet (UV)...

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 current-current correlators generated from lattice QCD. By including both data, our rigorously quantifies the uncertainties PDFs systematic effects intrinsic to observables. The significantly decrease on PDFs, while are limited by associated lattice. Consistent recent phenomenological determinations, behavior...

A bstract The non-singlet helicity quark parton distribution functions (PDFs) of the nucleon are determined from lattice QCD, by jointly leveraging pseudo-distributions and distillation spatial smearing paradigm. Lorentz decomposition appropriately isolated space-like matrix elements reveals that contain information on leading-twist PDFs, as well an invariant amplitude induces additional z 2 contamination signal. An analysis short-distance behavior using matching coefficients computed to...

A lattice QCD approach to the calculation of long-distance contributions <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>ε</a:mi><a:mi>K</a:mi></a:msub></a:math> is presented. This parameter describes indirect <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mi>C</c:mi><c:mi>P</c:mi></c:mrow></c:math> violation in <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>K</e:mi><e:mo...

A bstract Lattice QCD offers the possibility of computing parton distributions from first principles, although not in usual $$ \overline{MS} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>MS</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> factorization scheme. Calculations are therefore matched to using a perturbative procedure which is source significant uncertainty within currently accessible kinematics. We present z 2 evolution non-singlet pseudo-parton...

Ioffe-time distributions, which are functions of the ν , Fourier transforms parton distribution with respect to momentum fraction variable x. These distributions can be obtained from suitable equal time, quark bilinear hadronic matrix elements calculated first principles in lattice QCD, as it has been recently argued. In this talk I present numerical calculation nucleon quenched approximation.

We demonstrate a new method of extracting parton distributions from lattice calculations. The starting idea is to treat the generic equal-time matrix element ${\cal M} (Pz_3, z_3^2)$ as function Ioffe time $ν= Pz_3$ and distance $z_3$. next step divide by rest-frame density (0, z_3^2)$. Our calculation shows linear exponential $z_3$-dependence in function, expected $Z(z_3^2)$ factor generated gauge link. Still, we observe that ratio (Pz_3 , z_3^2)/{\cal has Gaussian-type behavior with...

Using the Coulomb gauge formulation of QED we present a lattice QCD procedure to calculate $\pi^+\pi^+$ scattering phase shift including effects potential which appears in this formulation. The approach described here incorporates relativity and avoids finite-volume corrections that vanish as power volume calculation is performed. This first step developing complete electromagnetic isospin-breaking light-quark mass contributions $\varepsilon'$, parameter describing direct CP violating...

We present an exploration of the unpolarized isovector proton generalized parton distributions (GPDs) $H^{u-d}(x, \xi, t)$ and $E^{u-d}(x, in pseudo-distribution formalism using distillation. Taking advantage large kinematic coverage made possible by this approach, we results on moments GPDs up to order $x^3$ -- including their skewness dependence at a pion mass $m_\pi = 358$ MeV lattice spacing $a 0.094$ fm.