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Related papers: Proton Spin Structure from Lattice QCD

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We present a lattice QCD calculation of transverse momentum dependent parton distribution functions (TMDs) of protons using staple-shaped Wilson lines. For time-reversal odd observables, we calculate the generalized Sivers and Boer-Mulders…

High Energy Physics - Lattice · Physics 2016-01-22 B. Yoon , T. Bhattacharya , M. Engelhardt , J. Green , R. Gupta , P. Hägler , B. Musch , J. Negele , A. Pochinsky , S. Syritsyn

We present results for the matrix elements relevant for proton decay in Grand Unified Theories (GUTs). The calculation is performed at a fixed lattice spacing a^{-1}=1.73(3) GeV using 2+1 flavors of domain wall fermions on lattices of size…

High Energy Physics - Lattice · Physics 2009-01-09 Y. Aoki , P. Boyle , P. Cooney , L. Del Debbio , R. Kenway , C. M. Maynard , A. Soni , R. Tweedie

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 the first calculation of the kaon semileptonic form factor with sea and valence quark masses tuned to their physical values in the continuum limit of 2+1 flavour domain wall lattice QCD. We analyse a comprehensive set of…

This article reviews our present understanding of the QCD spin structure of the proton. We first outline the proton spin puzzle and its possible resolution in QCD. We then review the present and next generation of experiments to resolve the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Steven D. Bass

We generate $2+1$ flavor QCD configurations near the physical point on a $96^4$ lattice employing the 6-APE stout smeared Wilson clover action with a nonperturbative $c_{\rm SW}$ and the Iwasaki gauge action at $\beta=1.82$. The physical…

High Energy Physics - Lattice · Physics 2015-12-01 K. -I. Ishikawa , N. Ishizuka , Y. Kuramashi , Y. Nakamura , Y. Namekawa , Y. Taniguchi , N. Ukita , T. Yamazaki , T. Yoshie

We report a calculation of the nucleon axial form factors $G_A^q(Q^2)$ and $G_P^q(Q^2)$ for all three light quark flavors $q\in\{u,d,s\}$ in the range $0\leq Q^2\lesssim 1.2\text{ GeV}^2$ using lattice QCD. This work was done using a single…

QCD with eight flavors is studied on $16^3\times N_t$ lattices with $N_t=4$, 6, 8, 16 and 32, a dynamical quark mass $ma=0.015$ and lattice coupling $\beta=6/g^2$ between 4.5 and 5.0. For $N_t=16$ and 32, hadron masses and screening lengths…

High Energy Physics - Lattice · Physics 2016-08-31 Frank R. Brown , Hong Chen , Norman H. Christ , Zhihua Dong , Robert D. Mawhinney , Wendy Schaffer , Alessandro Vaccarino

In view of the recent excitement about a tension between determinations of f_Ds from experiment and from simulations of lattice QCD with dynamical quarks, we try to clear up the picture of lattice determinations in the continuum limit of…

High Energy Physics - Lattice · Physics 2011-04-04 Jochen Heitger , Andreas Juttner

First results of a recently started simulation of full QCD with two flavours of sea-quarks at a coupling of $\beta = 5.6$ on a $16^3 \times 32$ lattice are presented. Emphasis is laid on the statistical significance that can be achieved by…

High Energy Physics - Lattice · Physics 2019-08-17 SESAM-Collaboration , : , U. Glässner , S. Güsken , H. Hoeber , Th. Lippert , X. Luo , G. Ritzenhöfer , K. Schilling , G. Siegert

We present results for the isoscalar electromagnetic form factors of the nucleon computed on the Coordinated Lattice Simulations (CLS) ensembles with $N_\mathrm{f} = 2 + 1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an…

High Energy Physics - Lattice · Physics 2022-09-21 Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Miguel Salg , Jonas Wilhelm , Hartmut Wittig

The current status of some nucleon isovector observables, the vector charge, \(g_V\), axial charge, \(g_A\), quark momentum fraction, \(\langle x \rangle_{u-d}\), and quark helicity fraction, \(\langle x \rangle_{\Delta u - \Delta d}\),…

High Energy Physics - Lattice · Physics 2019-08-14 Shigemi Ohta

We present a first scaling test of twisted mass QCD with pure Wilson quarks for a twisting angle of pi/2. We have computed the vector meson mass and the pseudoscalar decay constant for different values of beta at fixed value of r_0 m_PS.…

High Energy Physics - Lattice · Physics 2009-11-10 Karl Jansen , Andrea Shindler , Carsten Urbach , Ines Wetzorke

We present 2+1 flavor Lattice QCD calculations of the nucleon scalar and tensor charges. Using the BMW clover-improved Wilson action with pion masses between 150 and 350 MeV and three source-sink separations between 0.9 and 1.4 fm, we…

High Energy Physics - Lattice · Physics 2013-05-30 J. R. Green , J. W. Negele , A. V. Pochinsky , S. N. Syritsyn , M. Engelhardt , S. Krieg

We present a new method to evaluate with high precision the isospin breaking effects due to the mass difference between the up and down quarks using lattice QCD. Our proposal is applicable in principle to any hadronic observable which can…

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 report isovector form factors and low moments of isovector structure functions of nucleon from the coarse RIKEN-BNL-Columbia (RBC) and UKQCD joint dynamical (2+1)-flavor domain-wall fermions (DWF) ensembles. The lattice cut off is…

High Energy Physics - Lattice · Physics 2008-10-02 Shigemi Ohta , Takeshi Yamazaki

We compute both sides of the Witten-Veneziano formula using lattice techniques. For the one side we perform dedicated quenched simulations and use the spectral projector method to determine the topological susceptibility in the pure…

High Energy Physics - Lattice · Physics 2015-10-20 Krzysztof Cichy , Elena Garcia-Ramos , Karl Jansen , Konstantin Ottnad , Carsten Urbach

We present the first quenched lattice QCD study of the form factors relevant for the hyperon semileptonic decay Sigma -> n l nu. The momentum dependence of both axial and vector form factors is investigated and the values of all the form…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. Guadagnoli , V. Lubicz , M. Papinutto , S. Simula

We review recent progress on lattice calculations of nucleon spin structure, including the parton distribution functions, form factors, generalization parton distributions, and recent developments in lattice techniques.

High Energy Physics - Lattice · Physics 2009-08-24 Huey-Wen Lin