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Related papers: FLAVOR-SINGLET g_A FROM LATTICE QCD

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We compute the condensate in QCD with a single quark flavor using numerical simulations with the overlap formulation of lattice fermions. The condensate is extracted by fitting the distribution of low lying eigenvalues of the Dirac operator…

High Energy Physics - Theory · Physics 2009-11-11 Thomas DeGrand , Roland Hoffmann , Stefan Schaefer , Zhaofeng Liu

We show the first lattice QCD results on the axial charge $g_A^{N^*N^*}$ of $N^*(1535)$ and $N^*(1650)$. The measurements are performed with two flavors of dynamical quarks employing the renormalization-group improved gauge action at…

High Energy Physics - Lattice · Physics 2008-11-26 Toru T. Takahashi , Teiji Kunihiro

In a recent letter [Phys. Rev. Lett. 108, 172003 (2012), arXiv:1109.2480] we have reported on a lattice QCD calculation of the heavy-hadron axial couplings $g_1$, $g_2$, and $g_3$. These quantities are low-energy constants of heavy-hadron…

High Energy Physics - Lattice · Physics 2012-06-19 William Detmold , C. -J. David Lin , Stefan Meinel

In this work, we present the first-ever calculation of the isovector flavor combination of the twist-3 parton distribution function $g_T(x)$ for the proton from lattice QCD. We use an ensemble of gauge configurations with two degenerate…

High Energy Physics - Lattice · Physics 2020-12-30 Shohini Bhattacharya , Krzysztof Cichy , Martha Constantinou , Andreas Metz , Aurora Scapellato , Fernanda Steffens

We perform a non-perturbative determination of the improvement coefficient c_A to remove O(a) discretization errors in the axial vector current in three-flavor lattice QCD with the Iwasaki gauge action and the standard O$(a)$-improved…

High Energy Physics - Lattice · Physics 2010-10-27 T. Kaneko , S. Aoki , M. Della Morte , S. Hashimoto , R. Hoffmann , R. Sommer

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 present results for the form factors of the isovector axial vector current in the nucleon state using large scale simulations of lattice QCD. The calculations were done using eight ensembles of gauge configurations generated by the MILC…

High Energy Physics - Lattice · Physics 2017-12-13 Rajan Gupta , Yong-Chull Jang , Huey-Wen Lin , Boram Yoon , Tanmoy Bhattacharya

We report on our calculation of the nucleon axial charge gA in QCD with two flavours of dynamical quarks. A detailed investigation of systematic errors is performed, with a particular focus on contributions from excited states to…

High Energy Physics - Lattice · Physics 2013-09-26 S. Capitani , M. Della Morte , G. von Hippel , B. Jäger , A. Jüttner , B. Knippschild , H. B. Meyer , H. Wittig

A combination of lattice and continuum data for the light-quark V-A correlator, supplemented by results from a chiral sum-rule analysis of the flavor-breaking flavor $ud$-$us$ V-A correlator difference, is shown to make possible a…

High Energy Physics - Phenomenology · Physics 2013-11-05 P. A. Boyle , L. Del Debbio , N. Garron , R. J. Hudspith , E. Kerrane , K. Maltman , J. M. Zanotti

We report on our Ward identity determination of the $\mathrm{O}(a)$ improvement coefficient for the flavour singlet scalar density, namely $g_\mathrm{S}$, from three-flavour lattice QCD with Wilson-clover fermions and the tree-level…

High Energy Physics - Lattice · Physics 2025-02-14 Pia Leonie Jones Petrak , Jochen Heitger , Fabian Joswig

We present an extensive study on the direct determination of the running coupling alpha_s from the static quark antiquark force at short distances, in quenched QCD. We find from our high statistics potential analysis that alpha_qq exhibits…

High Energy Physics - Lattice · Physics 2011-07-19 K. Schilling , G. S. Bali

We present a determination of the QCD parameter Lambda in the quenched approximation (n_f=0) and for two flavours (n_f=2) of light dynamical quarks. The calculations are performed on the lattice using O(a) improved Wilson fermions and…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Göckeler , R. Horsley , A. C. Irving , D. Pleiter , P. E. L. Rakow , G. Schierholz , H. Stüben

We report on a non-perturbative computation of the renormalization factor Z_A of the axial vector current in three-flavour O(a) improved lattice QCD with Wilson quarks and tree-level Symanzik improved gauge action and also recall our recent…

High Energy Physics - Lattice · Physics 2015-03-02 John Bulava , Michele Della Morte , Jochen Heitger , Christian Wittemeier

The axial charge of the nucleon $g_A$ and the pion decay constant $f_\pi$ are computed in two-flavor lattice QCD. The simulations are carried out on lattices of various volumes and lattice spacings. Results are reported for pion masses as…

High Energy Physics - Lattice · Physics 2015-06-15 R. Horsley , Y. Nakamura , A. Nobile , P. E. L. Rakow , G. Schierholz , J. M. Zanotti

We present the first chiral-continuum extrapolated up, down and strange quark spin contribution to the proton spin using lattice QCD. For the connected contributions, we use eleven ensembles of 2+1+1-flavor of Highly Improved Staggered…

High Energy Physics - Lattice · Physics 2018-12-05 Huey-Wen Lin , Rajan Gupta , Boram Yoon , Yong-Chull Jang , Tanmoy Bhattacharya

We present results for $f_B$, $f_{B_s}$, $f_D$, $f_{D_s}$ and their ratios in the presence of two flavors of light sea quarks ($N_f=2$). We use Wilson light valence quarks and Wilson and static heavy valence quarks; the sea quarks are…

High Energy Physics - Lattice · Physics 2008-11-26 The MILC Collaboration , C. Bernard , S. Datta , T. DeGrand , C. DeTar , Steven Gottlieb , Urs M. Heller , C. McNeile , K. Orginos , R. Sugar , D. Toussaint

We study the nature of the QCD vacuum at general number of flavors $N_F$ by numerical simulations on the lattice. Combining the results with those of the perturbation theory, we propose the following picture: 1) For $N_F \ge 17$, there…

High Energy Physics - Lattice · Physics 2009-09-25 Y. Iwasaki , K. Kanaya , S. Kaya , T. Yoshié , S. Sakai

We present the full results of the Wuppertal-Budapest lattice QCD collaboration on flavor diagonal and non-diagonal quark number susceptibilities with 2+1 staggered quark flavors, in a temperature range between 125 and 400 MeV. The light…

High Energy Physics - Lattice · Physics 2015-06-03 Szabolcs Borsanyi , Zoltan Fodor , Sandor D. Katz , Stefan Krieg , Claudia Ratti , Kalman Szabo

We present data testing the existence of a parity-flavor breaking phase in simulations of QCD with two flavors of light Wilson fermions. This is done by explicit simulations on lattice sizes of $6^4$, $8^4$ and $10^4$ for a variety of…

High Energy Physics - Lattice · Physics 2009-10-28 Khalil M. Bitar

We present our progress on the computation of the axial form factor of the nucleon with flavour structure $u+d-2s$ from lattice QCD. We employ a set of $N_f=2+1$ CLS ensembles with $O(a)$-improved Wilson fermions and the L\"uscher-Weisz…