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Related papers: Nucleon Axial and Electromagnetic Form Factors

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The current status is reported of joint lattice numerical calculations by LHP and RBC collaborations of isovector nucleon form factors using 2+1-flavor physical-mass domain-wall fermions ensemble at a lattice cutoff $a^{-1}$ of 1.730(4) GeV…

High Energy Physics - Lattice · Physics 2021-11-29 Shigemi Ohta

Extending a recent suggestion for hyperon form factors to the nucleon case, dispersion theory is used to relate the low-energy vector-isovector form factors of the nucleon to the pion vector form factor. The additionally required input,…

High Energy Physics - Phenomenology · Physics 2018-02-14 Stefan Leupold

In light of the improved precision of the experimental measurements and enormous theoretical progress, the nucleon form factors have been evaluated with an aim to understand how the static properties and dynamical behavior of nucleons…

High Energy Physics - Phenomenology · Physics 2017-11-03 Harleen Dahiya , Monika Randhawa

We present a dedicated analysis of the influence of excited states on the calculation of nucleon matrix elements. This calculation is performed at a fixed value of the lattice spacing, volume and pion mass that are typical of contemporary…

High Energy Physics - Lattice · Physics 2015-05-30 Simon Dinter , Constantia Alexandrou , Martha Constantinou , Vincent Drach , Karl Jansen , Dru B. Renner

We present preliminary results for the axial, scalar and tensor charges of the nucleon measured in 2+1 flavor QCD with the physical light quarks ($m_\pi=135$ MeV). Our simulations are carried out with gauge configurations generated by the…

High Energy Physics - Lattice · Physics 2023-01-18 Ryutaro Tsuji , Yasumichi Aoki , Ken-Ichi Ishikawa , Yoshinobu Kuramashi , Shoichi Sasaki , Eigo Shintani , Takeshi Yamazaki

We study the nucleon electromagnetic form factors (EM FFs) using a recently developed method combining Chiral Effective Field Theory ($\chi$EFT) and dispersion analysis. The spectral functions on the two-pion cut at $t > 4 M_\pi^2$ are…

High Energy Physics - Phenomenology · Physics 2018-05-16 J. M. Alarcón , C. Weiss

We investigate the pion and kaon (pi^+, K^+, K^0) electromagnetic form factors in the space-like region: Q^2 ~< 1 GeV, based on the gauged low-energy effective chiral action from the instanton vacuum in the large N_c limit. Explicit flavor…

High Energy Physics - Phenomenology · Physics 2008-11-26 Seung-il Nam , Hyun-Chul Kim

We evaluate the nucleon axial form factor, $G_A(q^2)$, and induced pseudoscalar form factor, $G_p(q^2)$, as well as the pion-nucleon form factor, $G_{\pi N N}(q^2)$, in lattice QCD. We also evaluate the corresponding nucleon to $\Delta$…

High Energy Physics - Lattice · Physics 2014-11-18 C. Alexandrou , G. Koutsou , Th. Leontiou , J. W. Negele , A. Tsapalis

We calculate the electromagnetic, axial and pseudo-scalar form factors of the Nucleon to $\Delta(1232)$ transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion action.…

High Energy Physics - Lattice · Physics 2011-02-25 C. Alexandrou , G. Koutsou , J. W. Negele , Y. Proestos , A. Tsapalis

High statistics results for the isovector momentum fraction, $\langle x \rangle_{u-d}$, helicity moment, $\langle x \rangle_{\Delta u-\Delta d}$, and the transversity moment, $\langle x\rangle_{\delta u-\delta d}$, of the nucleon are…

High Energy Physics - Lattice · Physics 2021-06-11 Santanu Mondal , Rajan Gupta , Sungwoo Park , Boram Yoon , Tanmoy Bhattacharya , Bálint Joó , Frank Winter

The electromagnetic form factors of the proton and the neutron in the timelike region are investigated. Electron-positron annihilation into antinucleon-nucleon ($\bar NN$) pairs is treated in distorted wave Born approximation, including the…

Nuclear Theory · Physics 2023-12-06 Qin-He Yang , Ling-Yun Dai , Di Guo , Johann Haidenbauer , Xian-Wei Kang , Ulf-G. Meißner

The theoretical and experimental status of the isovector axial-vector current form factors G_A(q^2) and G_P(q^2) of the nucleon is reviewed. We also describe a new calculation of these form factors in manifestly Lorentz-invariant chiral…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. R. Schindler , S. Scherer

We present new parameterizations of vector and axial nucleon form factors. We maintain an excellent descriptions of the form factors at low momentum transfers ($Q^2$), where the spatial structure of the nucleon is important, and use the…

High Energy Physics - Experiment · Physics 2008-11-26 A. Bodek , S. Avvakumov , R. Bradford , H. Budd

Unitary and analytic ten-resonance model of the nucleon electromagnetic (e.m.) structure with canonical normalizations and QCD (up to the logarithmic correction) asymptotics is constructed on the four-sheeted Riemann surface, which provides…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stanislav Dubnicka , Anna-Zuzana Dubnickova , Peter Weisenpacher

In this work we present the isovector flavor combination for the nucleon tensor charge extracted from lattice QCD simulations using overlap fermions on $N_f=2+1$ domain-wall configurations. The pion mass dependence is studied using six…

High Energy Physics - Lattice · Physics 2020-05-13 Derek Horkel , Yujiang Bi , Martha Constantinou , Terrence Draper , Jian Liang , Keh-Fei Liu , Zhaofeng Liu , Yi-Bo Yang

We present results on the nucleon form factors, momentum fraction and helicity moment for $N_f=2$ and $N_f=2+1+1$ twisted mass fermions for a number of lattice volumes and lattice spacings. First results for a new $N_f=2$ ensemble at the…

High Energy Physics - Lattice · Physics 2013-12-11 C. Alexandrou , M. Constantinou , V. Drach , K. Jansen , Ch. Kallidonis , G. Koutsou

We calculate the electromagnetic and the axial form factors of the nucleon within the framework of light cone sum rules (LCSR) to leading order in QCD and including higher twist corrections. In particular we motivate a certain choice for…

High Energy Physics - Phenomenology · Physics 2009-11-11 V. M. Braun , A. Lenz , M. Wittmann

We give an update on our ongoing efforts to compute the nucleon's form factors and moments of structure functions using Nf=2 flavours of non-perturbatively improved Clover fermions. We focus on new results obtained on gauge configurations…

The electromagnetic form factors of the proton and the neutron are computed within lattice QCD using simulations with quarks masses fixed to their physical values. Both connected and disconnected contributions are computed. We analyze two…

High Energy Physics - Lattice · Physics 2019-08-28 C. Alexandrou , S. Bacchio , M. Constantinou , J. Finkenrath , K. Hadjiyiannakou , K. Jansen , G. Koutsou , A. Vaquero Aviles Casco

The extraction of the magnetic form factor of the nucleon at zero momentum transfer is usually performed by adopting a parametrization for its momentum dependence and fitting the results obtained at finite momenta. We present a position…

High Energy Physics - Lattice · Physics 2016-11-08 Constantia Alexandrou , Martha Constantinou , Giannis Koutsou , Konstantin Ottnad , Marcus Petschlies