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Related papers: Pion valence quark PDF from lattice QCD

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One of the great challenges of QCD is to determine the partonic structure of the nucleon from first principles. In this work, we provide such a determination of the flavor non-singlet ($u-d$) unpolarized parton distribution function (PDF),…

High Energy Physics - Lattice · Physics 2021-03-03 Manjunath Bhat , Krzysztof Cichy , Martha Constantinou , Aurora Scapellato

We present a state-of-the-art calculation of the isovector quark helicity Bjorken-$x$ distribution in the proton using lattice-QCD ensembles at the physical pion mass. We compute quasi-distributions at proton momenta $P_z \in \{2.2, 2.6,…

High Energy Physics - Lattice · Physics 2019-01-29 Huey-Wen Lin , Jiunn-Wei Chen , Xiangdong Ji , Luchang Jin , Ruizi Li , Yu-Sheng Liu , Yi-Bo Yang , Jian-Hui Zhang , Yong Zhao

We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a…

High Energy Physics - Lattice · Physics 2016-04-20 Constantia Alexandrou

Lattice simulations of QCD have produced precise estimates for the masses of the lowest-lying hadrons which show excellent agreement with experiment. By contrast, lattice results for the vector and axial vector form factors of the nucleon…

High Energy Physics - Lattice · Physics 2011-09-23 B. B. Brandt , S. Capitani , M. Della Morte , D. Djukanovic , J. Gegelia , G. von Hippel , A. Juttner , B. Knippschild , H. B. Meyer , H. Wittig

In this paper, we present lattice QCD results for the $x$-dependence of the unpolarized gluon PDF for the proton. We use one ensemble of $N_f=2+1+1$ maximally twisted mass fermions with a clover improvement, and the Iwasaki improved gluon…

High Energy Physics - Lattice · Physics 2023-10-03 Joseph Delmar , Constantia Alexandrou , Krzysztof Cichy , Martha Constantinou , Kyriakos Hadjiyiannakou

The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression…

A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition…

High Energy Physics - Phenomenology · Physics 2020-04-22 Minghui Ding , Khépani Raya , Daniele Binosi , Lei Chang , Craig D. Roberts , Sebastian M. Schmidt

One proposal to compute parton distributions from first principles is the large momentum effective theory (LaMET), which requires the Fourier transform of matrix elements computed non-perturbatively. Lattice quantum chromodynamics (QCD)…

The electromagnetic form factor of the pion is calculated in the "point-form" of relativistic quantum mechanics using simple, phenomenological wave functions. It is found that the squared charge radius of the pion is predicted one order of…

High Energy Physics - Phenomenology · Physics 2015-06-25 A. Amghar , B. Desplanques , L. Theussl

I discuss the properties of pions in ``partially quenched'' theories, i.e. those in which the valence and sea quark masses, $m_V$ and $m_S$, are different. I point out that for lattice fermions which retain some chiral symmetry on the…

High Energy Physics - Lattice · Physics 2014-11-17 Stephen R. Sharpe

In large-momentum effective theory (LaMET), calculating parton physics starts from calculating coordinate-space-$z$ correlation functions $\tilde h(z, a,P^z)$ in a hadron of momentum $P^z$ in lattice QCD. Such correlation functions involve…

High Energy Physics - Phenomenology · Physics 2021-01-20 Xiangdong Ji , Yizhuang Liu , Andreas Schäfer , Wei Wang , Yi-Bo Yang , Jian-Hui Zhang , Yong Zhao

We apply a classical mathematical problem, the moment problem, with its related mathematical achievements, to the study of the parton distribution function (PDF) in hadron physics, and propose a strategy to sieve the moments of the PDF by…

High Energy Physics - Phenomenology · Physics 2023-10-27 Xiaobin Wang , Minghui Ding , Lei Chang

Measurements of the $\Lambda_b \to p \ell^- \bar{\nu}_\ell$ and $\Lambda_b \to \Lambda_c \ell^- \bar{\nu}_\ell$ decay rates can be used to determine the magnitudes of the CKM matrix elements $V_{ub}$ and $V_{cb}$, provided that the relevant…

High Energy Physics - Lattice · Physics 2015-08-05 William Detmold , Christoph Lehner , Stefan Meinel

In this work, we perform a lattice QCD calculation of the branching ratios and the form factors of radiative leptonic decays $P \to \ell \nu_\ell \gamma$ ($P = \pi, K$) using $N_f=2+1$ domain wall fermion ensembles generated by the RBC and…

High Energy Physics - Lattice · Physics 2026-04-29 Peter Boyle , Norman H. Christ , Xu Feng , Taku Izubuchi , Luchang Jin , Christopher T. Sachrajda , Xin-Yu Tuo

We present a calculation of the pion quark momentum fraction, $\langle x \rangle$, and its third Mellin moment $\langle x^2 \rangle$. We also obtain directly, for the first time, $\langle x \rangle$ and $\langle x^2 \rangle$ for the kaon…

The universality of the large momentum expansion allows computing parton distribution functions (PDFs) starting from any Euclidean correlator with appropriate large momentum Fourier Components. Here we consider current-current correlators…

High Energy Physics - Phenomenology · Physics 2026-05-06 Jialu Zhang , Xiangdong Ji , Andreas Schäfer , Rui Zhang , Christian Zimmermann

We present the first attempt of a new method to compute the pion light-cone wave function (LCWF) on the lattice. We compute the matrix element between the pion and the vacuum of a non-local operator: the propagator of a ``scalar quark''…

High Energy Physics - Phenomenology · Physics 2016-08-16 A. Abada , Ph. Boucaud , G. Herdoiza , J. P. Leroy , J. Micheli , O. Pène , J. Rodríguez-Quintero

Following the proposal in [1], we study the feasibility to calculate the pion distribution amplitude (DA) from suitably chosen Euclidean correlation functions at large momentum. In our lattice study we employ the novel momentum smearing…

We present the first determination of the $x$-dependent pion gluon distribution from lattice QCD using the pseudo-PDF approach. We use lattice ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ), generated by MILC…

High Energy Physics - Lattice · Physics 2021-11-17 Zhouyou Fan , Huey-Wen Lin

In this work, we investigate the constituent parton distribution functions (PDFs) of the kaon and heavy pseudoscalar mesons within the light-cone quark model. Starting from the initial scale quark and antiquark PDFs, obtained by evaluating…

High Energy Physics - Phenomenology · Physics 2026-05-19 Satyajit Puhan