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Related papers: Multipole structure of the nucleon tensor form fac…

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We present results for the isovector electromagnetic form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an $\mathcal{O}(a)$-improved vector current. The analysis…

High Energy Physics - Lattice · Physics 2021-06-02 D. Djukanovic , T. Harris , G. von Hippel , P. M. Junnarkar , H. B. Meyer , D. Mohler , K. Ottnad , T. Schulz , J. Wilhelm , H. Wittig

We compute the axial and pseudoscalar form factors of the nucleon in the Dyson-Schwinger approach. To this end, we solve a covariant three-body Faddeev equation for the nucleon wave function and determine the matrix elements of the…

High Energy Physics - Phenomenology · Physics 2015-06-03 Gernot Eichmann , Christian S. Fischer

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 investigate the imaginary parts of the nucleon electromagnetic and axial form factors close to threshold in the framework of heavy baryon chiral perturbation theory. For the isovector electromagnetic form factors, we recover the well…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Bernard , N. Kaiser , Ulf-G. Meißner

Utilizing the methods of chiral effective field theory we present an analysis of the electromagnetic $N\Delta$-transition current in the framework of the non-relativistic "small scale expansion" (SSE) to leading-one-loop order. We discuss…

Nuclear Theory · Physics 2008-11-26 Tobias A. Gail , Thomas R. Hemmert

We study the electromagnetic form factors of a nucleon in next-to-leading order chiral perturbation theory (CPT) in the case where one of the nucleons is off its mass shell. We calculate the leading nonanalytic contributions to relevant…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. W. Bos , J. H. Koch

We investigate the singlet $g_T^{(0)}$ and isovector $g_T^{(3)}$ tensor charges of the nucleon, which are deeply related to the first moment of the leading twist transversity quark distribution $h_1(x)$, in the chiral quark-soliton model.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hyun-Chul Kim , M. V. Polyakov , K. Goeke

The chiral quark model posits pseudoscalar and vector meson couplings to constituent quarks. The parity violating meson-quark couplings lead to anapole moments and form factors of the nucleons. These arise both as parity violating meson…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. O. Riska

We present results on the isoscalar form factors including the disconnected contributions, as well as on the strange and charm quark form factors. Using previous results on the isovector form factors, we determine the flavor decomposition…

High Energy Physics - Lattice · Physics 2021-10-13 C. Alexandrou , S. Bacchio , M. Constantinou , K. Hadjiyiannakou , K. Jansen , G. Koutsou

We present a numerical lattice quantum chromodynamics calculation of isovector form factors and the first few moments of the isovector structure functions of the nucleon. The calculation employs two degenerate dynamical flavors of…

High Energy Physics - Lattice · Physics 2008-12-18 Huey-Wen Lin , Tom Blum , Shigemi Ohta , Shoichi Sasaki , Takeshi Yamazaki

We apply the perturbative chiral quark model at one loop to calculate the strange form factors of the nucleon. A detailed numerical analysis of the strange magnetic moments and radii of the nucleon, and also the momentum dependence of the…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. E. Lyubovitskij , P. Wang , Th. Gutsche , Amand Faessler

We calculate the deuteron charge, electric quadrupole, and magnetic form factors up to next-to-next-to-leading order in chiral effective field theory, treating subleading corrections, especially that of chiral nuclear forces, in…

Nuclear Theory · Physics 2022-07-29 Wenchao Shi , Rui Peng , Tai-Xing Liu , Songlin Lyu , Bingwei Long

The nonlocal chiral effective theory is applied to investigate the electromagnetic and strange form factors of nucleon. The bubble and tadpole diagrams are included in the calculation. With the contributions from bubble and tadpole…

High Energy Physics - Phenomenology · Physics 2023-02-06 Z. Y. Gao , P. Wang , M. Y. Yang

The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the…

High Energy Physics - Phenomenology · Physics 2009-12-30 Randy Lewis , Nader Mobed

We report our numerical lattice QCD calculations of the isovector nucleon form factors for the vector and axialvector currents: the vector, induced tensor, axialvector, and induced pseudoscalar form factors. The calculation is carried out…

High Energy Physics - Lattice · Physics 2010-04-28 Takeshi Yamazaki , Yasumichi Aoki , Tom Blum , Huey-Wen Lin , Shigemi Ohta , Shoichi Sasaki , Robert Tweedie , James Zanotti

I discuss recent work on nucleon form factors, magnetic strangeness in the nucleon and the isovector nucleon-delta transition based on the broken chiral symmetry of QCD, utilizing recent theoretical developments in ChPT.

Nuclear Theory · Physics 2011-04-15 Thomas R. Hemmert

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

The axial form factor of the nucleon is studied in a two-component model consisting of a three-quark intrinsic structure surrounded by a meson cloud. The experimental data in the space-like region are well reproduced with a minimal number…

Nuclear Theory · Physics 2008-11-26 C. Adamuščín , E. Tomasi-Gustafsson , E. Santopinto , R. Bijker

We investigate the vector transition form factors of the nucleon and vector meson K^* to the pentaquark baryon Theta^+ within the framework of the SU(3) chiral quark-soliton model. We take into account the rotational 1/N_c and linear…

High Energy Physics - Phenomenology · Physics 2008-11-26 Tim Ledwig , Hyun-Chul Kim , Klaus Goeke

We present results on the nucleon axial and induced pseudo-scalar form factors using an ensemble of two degenerate twisted mass clover-improved fermions generated at the physical value of the pion mass. We evaluate the isovector and the…