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Related papers: Nucleon form factors with dynamical twisted mass f…

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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

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

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…

Nuclear Theory · Physics 2009-01-14 J. C. R. Bloch , C. D. Roberts , S. M. Schmidt , A. Bender , M. R. Frank

We present a calculation of the scalar, vector and tensor pion and kaon form factors using one ensemble of two degenerate light, a strange and a charm quark ($N_f=2+1+1$) of maximally twisted mass fermions with clover improvement. The quark…

The RBC and UKQCD collaborations have been investigating hadron physics in numerical lattice quantum chromodynamics (QCD) with (2+1) flavors of dynamical domain wall fermions (DWF) quarks that preserves continuum-like chiral and flavor…

High Energy Physics - Lattice · Physics 2019-08-15 Shigemi Ohta

We determine the nucleon axial, scalar and tensor charges at the continuum limit by analyzing three $N_f=2+1+1$ twisted mass fermion ensembles with all quark masses tuned to approximately their physical values. We include all contributions…

High Energy Physics - Lattice · Physics 2025-02-11 Constantia Alexandrou , Simone Bacchio , Jacob Finkenrath , Christos Iona , Giannis Koutsou , Yan Li , Gregoris Spanoudes

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 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…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. A. Ivanov , M. P. Locher , V. E. Lyubovitskij

We present recent lattice results on the baryon spectrum, nucleon electromagnetic and axial form factors, nucleon to $\Delta$ transition form factors as well as the $\Delta$ electromagnetic form factors. The masses of the low lying baryons…

High Energy Physics - Lattice · Physics 2015-05-13 C. Alexandrou

The proton's elastic electromagnetic form factors are calculated using an Ansatz for the nucleon's Poincare' covariant Faddeev amplitude that only retains scalar diquark correlations. A spectator approximation is employed for the current.…

Nuclear Theory · Physics 2009-01-14 J. C. R. Bloch , A. Krassnigg , C. D. Roberts

We present results on the axial and the electromagnetic form factors of the nucleon, as well as, on the first moments of the nucleon generalized parton distributions using maximally twisted mass fermions. We analyze two N_f=2+1+1 ensembles…

High Energy Physics - Lattice · Physics 2013-08-09 C. Alexandrou , M. Constantinou , S. Dinter , V. Drach , K. Jansen , C. Kallidonis , G. Koutsou

We present results on the spin and quark content of the nucleon using $N_f=2$ twisted mass clover-improved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate results for…

High Energy Physics - Lattice · Physics 2016-11-29 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , Ch. Kallidonis , G. Koutsou , K. Jansen , Ch. Wiese , A. Vaquero Avilés-Casco

We develop techniques to calculate the four Delta electromagnetic form factors using lattice QCD, with particular emphasis on the sub-dominant electric quadrupole form factor that probes deformation of the Delta. Results are presented for…

High Energy Physics - Lattice · Physics 2010-04-21 C. Alexandrou , T. Korzec , G. Koutsou , Th. Leontiou , C. Lorcé , J. W. Negele , V. Pascalutsa , A. Tsapalis , M. Vanderhaeghen

Using the light front wave functions for the nucleons in a quark model in AdS/QCD, we calculate the nucleon electromagnetic form factors. The flavor decompositions of the nucleon form factors are calculated from the GPDs in this model. We…

High Energy Physics - Phenomenology · Physics 2014-01-07 Dipankar Chakrabarti , Chandan Mondal

We present new N_f=2 data for the nucleon generalized form factors, varying volume, lattice spacing and pion mass, down to 150 MeV. We also give an update of our direct calculation of the nucleon sigma term for a range of pion mass values…

High Energy Physics - Lattice · Physics 2013-12-04 G. S. Bali , S. Collins , B. Gläßle , M. Göckeler , J. Najjar , R. Rödl , A. Schäfer , R. Schiel , W. Söldner , A. Sternbeck , P. Wein

We develop a methodology that enables us to extract accurately the electromagnetic Delta form factors and their momentum dependence. We test our approach in the quenched approximation as a preparation for a study using dynamical fermions.…

High Energy Physics - Lattice · Physics 2008-11-26 Constantia Alexandrou , Tomasz Korzec , Theodoros Leontiou , John W. Negele , Antonios Tsapalis

The nucleon form factors of the energy-momentum tensor are studied in the large-Nc limit in the framework of the chiral quark-soliton model.

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Goeke , J. Grabis , J. Ossmann , M. V. Polyakov , P. Schweitzer , A. Silva , D. Urbano

We investigate nucleon tensor form factors in the large-$N_{c}$ limit. In this picture, the nucleon emerges as a state of the $N_c$ valence quarks, which were bound by pion mean fields that were created by the presence of the valence quarks…

High Energy Physics - Phenomenology · Physics 2025-01-22 Nam-Yong Ghim , Ho-Yeon Won , June-Young Kim , Hyun-Chul Kim

Form factors are Lorentz invariant functions describing the internal structure of a system. In particular, they encode how physical properties like, e.g., charge, energy, momentum, and pressure are spatially distributed. While nucleon…

High Energy Physics - Phenomenology · Physics 2024-02-02 Cédric Lorcé

We present an update on our results of nucleon form factors measured on a large-volume lattice $(8.1\rm{fm})^4$ at almost the physical point in 2+1 flavor QCD. The configurations are generated with the stout-smeared $\mathcal{O}(a)$…

High Energy Physics - Lattice · Physics 2018-04-18 Natsuki Tsukamoto , Ken-Ichi Ishikawa , Yoshinobu Kuramashi , Shoichi Sasaki , Takeshi Yamazaki