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Related papers: Precision Study of Excited State Effects in Nucleo…

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We present a detailed analysis of statistical and systematic errors in the calculation of matrix elements of iso-vector scalar, axial and tensor charges between a neutron and a proton state. These analyses are being done on dynamical…

High Energy Physics - Lattice · Physics 2015-02-02 Rajan Gupta , Tanmoy Bhattacharya , Anosh Joseph , Huey-Wen Lin , Boram Yoon

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

We present results for the nucleon electromagnetic and axial form factors using an N$_f$=2 twisted mass fermion ensemble with pion mass of about 131 MeV. We use multiple sink-source separations to identify excited state contamination.…

We present results for the nucleon electromagnetic form factors, including the momentum transfer dependence and derived quantities (charge radii and magnetic moment). The analysis is performed using O(a) improved Wilson fermions in Nf=2 QCD…

High Energy Physics - Lattice · Physics 2015-09-30 S. Capitani , M. Della Morte , D. Djukanovic , G. von Hippel , J. Hua , B. Jäger , B. Knippschild , H. B. Meyer , T. D. Rae , H. Wittig

We study the performance of all-mode-averaging (AMA) when used in conjunction with a locally deflated SAP-preconditioned solver, determining how to optimize the local block sizes and number of deflation fields in order to minimize the…

High Energy Physics - Lattice · Physics 2016-11-21 Georg von Hippel , Thomas D. Rae , Eigo Shintani , Hartmut Wittig

I present an overview of the calculations of the isovector axial vector form factor of the nucleon, $G_A(Q^2)$, using lattice QCD. Based on a comparison of results from various collaborations, a case is made that lattice results are now…

High Energy Physics - Lattice · Physics 2024-01-31 Rajan Gupta

A review of recent lattice calculations of nucleon structure and matrix elements of operators in nucleons is presented. It primarily covers developments in the calculation of the matrix elements of the scalar, tensor, pseudo-scalar,…

High Energy Physics - Lattice · Physics 2020-03-20 Tanmoy Bhattacharya , Rajan Gupta , Boram Yoon

We present results for the moments of nucleon isovector vector and axial generalised parton distribution functions computed within lattice QCD. Three ensembles of maximally twisted mass clover-improved fermions simulated with a physical…

We report lattice QCD results on the axial charges of ground and excited nucleon states of both parities. This is the first study of these quantities with approximately chiral (CI) fermions. Two energy levels in the range of the negative…

High Energy Physics - Lattice · Physics 2012-02-14 T. Maurer , T. Burch , L. Ya. Glozman , C. B. Lang , D. Mohler , A. Schäfer

Bottomonium S-wave states were studied using lattice NRQCD. Masses of ground and excited states were calculated using multiexponential fitting to a set of correlation functions constructed using both local and wavefunction-smeared…

High Energy Physics - Lattice · Physics 2011-11-15 Randy Lewis , R. M. Woloshyn

We compute the axial, scalar, tensor and pseudoscalar isovector couplings of the nucleon as well as the induced tensor and pseudoscalar charges in lattice simulations with $N_f=2$ mass-degenerate non-perturbatively improved…

We report isovector form factors and low moments of structure functions of nucleon in numerical lattice quantum chromodynamics (QCD) from the on-going calculations by the RIKEN-BNL-Columbia (RBC) and UKQCD Collaborations with (2+1)…

High Energy Physics - Lattice · Physics 2012-08-27 UKQCD Collaboration , Takeshi Yamazaki , Shigemi Ohta

Techniques to compute hadron properties from lattice QCD rely upon the limit of long time separation. For baryons, the signal-to-noise problem often restricts one to time separations that are not ideally long, and for which couplings to…

High Energy Physics - Lattice · Physics 2015-08-04 Brian C. Tiburzi

The nucleon-pion-state contribution to QCD two- and three-point functions used in the calculation of the axial form factors of the nucleon are studied in chiral perturbation theory. For physically small quark masses the nucleon-pion states…

High Energy Physics - Lattice · Physics 2018-08-28 Oliver Bar

We present high statistics ($\mathcal{O}(2\times 10^5)$ measurements) preliminary results on (i) the isovector charges, $g^{u-d}_{A,S,T}$, and form factors, $G^{u-d}_E(Q^2)$, $G^{u-d}_M(Q^2)$, $G^{u-d}_A(Q^2)$, $\widetilde G^{u-d}_P(Q^2)$,…

High Energy Physics - Lattice · Physics 2020-02-07 Sungwoo Park , Tanmoy Bhattacharya , Rajan Gupta , Yong-Chull Jang , Balint Joo , Huey-Wen Lin , Boram Yoon

We study the mass spectra of excited baryons with the use of the lattice QCD simulations. We focus our attention on the problem of the level ordering between the positive-parity excited state N'(1440) (the Roper resonance) and the…

High Energy Physics - Lattice · Physics 2009-11-11 Kiyoshi Sasaki , Shoichi Sasaki , Tetsuo Hatsuda

This talk summarizes the progress made since Lattice 2021 in understanding and controlling the contributions of towers of multihadron excited states with mass gaps starting lower than of radial excitations, and in increasing our confidence…

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

We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length $L=2.1$ fm and $L=2.8$ fm. Cut-off…

High Energy Physics - Lattice · Physics 2015-03-17 C. Alexandrou , M. Brinet , J. Carbonell , M. Constantinou , P. A. Harraud , P. Guichon , K. Jansen , T. Korzec , M. Papinutto

We present results on the lower moments of the nucleon generalized parton distri butions within lattice QCD using two dynamical flavors of degenerate twisted mass fermions. Our simulations are performed on lattices with three different…

High Energy Physics - Lattice · Physics 2011-07-05 C. Alexandrou , J. Carbonell , M. Constantinou , P. A. Harraud , P. Guichon , K. Jansen , C. Kallidonis , T. Korzec , M. Papinutto