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In an earlier work, the charge (vector) and matter (scalar) radial distributions of heavy-light mesons were measured in the quenched approximation on a 16^3 times 24 lattice with a quark-gluon coupling of 5.7, a lattice spacing of 0.17 fm,…

High Energy Physics - Lattice · Physics 2008-11-26 J. Koponen , A. M. Green , C. Michael , P. Pennanen

We present a calculation of the up, down, strange and charm quark masses performed within the lattice QCD framework. We use the twisted mass fermion action and carry out simulations that include in the sea two light mass-degenerate quarks,…

Parton distribution functions give the probability to find partons (quarks and gluons) in a hadron as a function of the fraction x of the proton's momentum carried by the parton. They are conventionally defined in terms of matrix elements…

High Energy Physics - Lattice · Physics 2009-10-28 Davison E. Soper

Parton distribution functions (PDFs) are nonperturbative quantities describing the relation between a hadron and quarks and gluons within it. We propose to extract PDFs from QCD global analysis of "data" generated by lattice QCD…

High Energy Physics - Phenomenology · Physics 2018-10-24 Yan-Qing Ma , Jian-Wei Qiu

A method for computing electromagnetic properties of hadrons in lattice QCD is described. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing enhanced electric charges, the dependence of the…

High Energy Physics - Lattice · Physics 2009-10-28 A. Duncan , E. Eichten , H. Thacker

We present a lattice QCD study of valence parton distribution inside the pion within the framework of Large Momentum Effective Theory. We use a mixed action approach with 1-HYP smeared valence Wilson clover quarks on 2+1 flavor HISQ sea…

The QCDSF/UKQCD collaboration has an ongoing program to calculate nucleon matrix elements with two flavours of dynamical O(a) improved Wilson fermions. Here we present recent results on the electromagnetic form factors, the quark momentum…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , Ph. Hägler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers , H. Stüben , J. M. Zanotti

Gravitational form factors (GFFs) of hadrons encode essential information about the internal distributions of mass, spin, pressure, and shear among their quark and gluon constituents. We compute the quark and gluon GFFs of the proton using…

High Energy Physics - Phenomenology · Physics 2025-06-10 Sreeraj Nair , Chandan Mondal , Siqi Xu , Xingbo Zhao , James P. Vary

We present a calculation of the scalar, vector and tensor pion and kaon form factors using one ensemble of two degenerate light, a strange and a charm quark ($N_f=2+1+1$) of maximally twisted mass fermions with clover improvement. The quark…

We compute the leptonic decay constants $f_{D^+}$, $f_{D_s}$, and $f_{K^+}$, and the quark-mass ratios $m_c/m_s$ and $m_s/m_l$ in unquenched lattice QCD using the experimentally determined value of $f_{\pi^+}$ for normalization. We use the…

In this work, we present the first results on the gluon parton distribution of the kaon from lattice quantum chromodynamics. We carry out the lattice calculation at pion mass around 310~MeV and two lattice spacings, 0.15 and 0.12~fm, using…

High Energy Physics - Lattice · Physics 2022-12-07 Alejandro Salas-Chavira , Zhouyou Fan , Huey-Wen Lin

Recent developments in lattice QCD calculation of flavor singlet nucleon matrix elements are reviewed. Substantial sea quark contributions are found in the $\pi$-$N\ \sigma$ term and the quark spin content of the nucleon such that the total…

High Energy Physics - Lattice · Physics 2009-10-28 Masanori Okawa

We calculate the lowest order charm and beauty parton distribution functions in and fragmentation functions into D and B mesons using the operator definitions of factorized perturbative QCD. In the vacuum, we find the leading corrections…

High Energy Physics - Phenomenology · Physics 2009-11-10 Rishi Sharma , Ivan Vitev , Ben-Wei Zhang

We perform the first Lattice calculation about the charmed hadron spin decomposition using overlap fermions on a 2+1 flavor RBC/UKQCD domain-wall gauge configurations at 0.083 fm with 300 MeV pion mass. It is found that the contributions of…

High Energy Physics - Lattice · Physics 2024-10-11 Fangcheng He , Jian Liang , Yi-Bo Yang

We present a computation of the charm quark's mass and the leptonic D-meson decay constants f_D and f_{D_s} in two-flavour lattice QCD with non-perturbatively O(a) improved Wilson quarks. Our analysis is based on the CLS configurations at…

High Energy Physics - Lattice · Physics 2013-12-31 Jochen Heitger , Georg M. von Hippel , Stefan Schaefer , Francesco Virotta

We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in…

High Energy Physics - Phenomenology · Physics 2015-06-05 H. Khanpour , Ali N. Khorramian , S. Atashbar Tehrani

We present a lattice-QCD calculation of the pion distribution amplitudes using large-momentum effective theory (LaMET). Our calculation is carried out using five ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ),…

High Energy Physics - Lattice · Physics 2021-08-11 Nicholas Juliano , Rui Zhang , Carson Honkala , Huey-Wen Lin

We reexamine the shapes of the strange quark parton distribution functions (PDFs) of the proton by means of quantum chromodynamics (QCD) analysis of {\hera} deep inelastic scattering cross section measurement at DESY, and inclusive gauge…

High Energy Physics - Phenomenology · Physics 2021-11-03 Alim Ruzi , Bo-Qiang Ma

The gravitational form factors (GFFs) of a hadron encode fundamental aspects of its structure, including its shape and size as defined from e.g., its energy density. This work presents a determination of the flavor decomposition of the GFFs…

High Energy Physics - Lattice · Physics 2024-06-25 Daniel C. Hackett , Dimitra A. Pefkou , Phiala E. Shanahan

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
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