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相关论文: Two-component model for the axial form factor of t…

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Using a Poincar\'e-covariant quark+diquark Faddeev equation and related symmetry-preserving weak interaction current, we deliver parameter-free predictions for the nucleon axialvector form factor, $G_A(Q^2)$, on the domain $0\leq…

高能物理 - 唯象学 · 物理学 2022-11-23 Chen Chen , Craig D. Roberts

We report the calculation of electromagnetic form factors of nucleons within a relativistic three-quark model with Gaussian shape for the nucleon-quark vertex. The allowed region for two adjustable parameters, the range parameter…

高能物理 - 唯象学 · 物理学 2007-05-23 M. A. Ivanov , M. P. Locher , V. E. Lyubovitskij

We apply the perturbative chiral quark model (PCQM) at one loop to analyze the axial form factor of the nucleon. This chiral quark model is based on an effective Lagrangian, where baryons are described by relativistic valence quarks and a…

高能物理 - 唯象学 · 物理学 2008-11-26 K. Khosonthongkee , V. E. Lyubovitskij , Th. Gutsche , Amand Faessler , K. Pumsa-ard , S. Cheedket , Y. Yan

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

高能物理 - 实验 · 物理学 2008-11-26 A. Bodek , S. Avvakumov , R. Bradford , H. Budd

A covariant, composite scalar diquark, Fadde'ev amplitude model for the nucleon is used to calculate pseudoscalar, isoscalar- and isovector-vector, axial-vector and scalar nucleon form factors. The last yields the nucleon sigma-term and…

核理论 · 物理学 2009-01-14 J. C. R. Bloch , C. D. Roberts , S. M. Schmidt

We study the nucleon electromagnetic form factors in a quark-gluon core model framework, which can be viewed as an extension of the Isgur-Karl model of baryons. Using this picture we derive nucleon electromagnetic dipole form factors at low…

高能物理 - 唯象学 · 物理学 2009-12-04 Xian-Qiao Yu

We compute the nucleon axial and pseudoscalar form factors using three $N_f=$2+1+1 twisted mass fermion ensembles with all quark masses tuned to approximately their physical values. The values of the lattice spacings of these three physical…

The strange form factors of the nucleon are studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. A comparison with the available experimental world data from the SAMPLE, PVA4, HAPPEX…

核理论 · 物理学 2008-11-26 R. Bijker

The axial-vector form factor of the nucleons is studied at a finite temperature using the holographic soft-wall model with the thermal dilaton field. We use the bulk interaction action known from the zero temperature case and apply the…

高能物理 - 唯象学 · 物理学 2023-11-27 Shahin Mamedov , Narmin Nasibova

For the first time, a phenomenological analysis of the experimental electromagnetic form factors of the nucleon, both in the timelike and spacelike regions, is performed by taking into account the effects of nonvalence components in the…

高能物理 - 唯象学 · 物理学 2009-02-16 J. P. B. C. de Melo , T. Frederico , E. Pace , S. Pisano , G. Salmè

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…

高能物理 - 唯象学 · 物理学 2017-11-03 Harleen Dahiya , Monika Randhawa

We study the electromagnetic structure of the nucleon within a hybrid constituent-quark model that comprises, in addition to the $3q$ valence component, also a $3q$+$\pi$ non-valence component. To this aim we employ a Poincar\'e-invariant…

高能物理 - 唯象学 · 物理学 2016-04-20 Daniel Kupelwieser , Wolfgang Schweiger

Evidences are updated and strengthened for the two-scales picture of low-energy nucleon structure as a compact `hard' valence quark core surrounded by a `soft' cloud of quark-antiquark pairs (the meson cloud). These considerations are…

核理论 · 物理学 2024-05-28 Norbert Kaiser , Wolfram Weise

We calculate the electric dipole form factor of the nucleon that arises as a low-energy manifestation of time-reversal violation in quark-gluon interactions of effective dimension 6: the quark electric and chromoelectric dipole moments, and…

高能物理 - 唯象学 · 物理学 2011-01-04 J. de Vries , E. Mereghetti , R. G. E. Timmermans , U. van Kolck

We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also…

We use a continuum quark+diquark approach to the nucleon bound-state problem in relativistic quantum field theory to deliver parameter-free predictions for the nucleon axial and induced pseudoscalar form factors, $G_A$ and $G_P$, and unify…

高能物理 - 唯象学 · 物理学 2022-06-01 Chen Chen , Christian S. Fischer , Craig D. Roberts , Jorge Segovia

The recent investigation on various form factors of the nucleon is reviewed in the framework of the SU(3) chiral quark-soliton model. The results for the electromagnetic and scalar form factors are in remarkable agreement with experimental…

高能物理 - 唯象学 · 物理学 2007-05-23 Hyun-Chul Kim

In treating the relativistic three-quark problem, a dressed-quark propagator parameterization is used which is compatible with recent lattice data and pion observables. Furthermore two-quark correlations are modeled as a series of quark…

高能物理 - 唯象学 · 物理学 2008-11-26 M. Oettel , R. Alkofer

A microscopic model of the electromagnetic form factor of the nucleon is developed in a hadronic framework, including pions, nucleons and the Delta-resonance explicitly. The space like on-shell form factors are reproduced and predictions…

核理论 · 物理学 2009-09-25 H. C. Doenges , M. Schaefer , U. Mosel

Nucleon form factors are calculated on q^2 in [0,3] GeV^2 using an Ansatz for the nucleon's Fadde'ev amplitude motivated by quark-diquark solutions of the relativistic Fadde'ev equation. Only the scalar diquark is retained, and it and the…

核理论 · 物理学 2009-01-14 J. C. R. Bloch , C. D. Roberts , S. M. Schmidt , A. Bender , M. R. Frank