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We compute the electromagnetic charged kaon form factor in the time-like region by employing a Poincar\'e covariant formalism of the Bethe-Salpeter equation to study quark-antiquark bound states in conjunction with the Schwinger-Dyson…

High Energy Physics - Phenomenology · Physics 2023-02-01 A. S. Miramontes , Adnan Bashir

The Chiral Quark-Soliton model provides the quark and antiquark substructure of the nucleon, which is embedded in nuclear matter. This provides a new way to asses the effects of the nuclear medium on the nucleon. We calculate nuclear…

Nuclear Theory · Physics 2009-09-29 Jason R. Smith

An approach for a unified description of the nucleon electromagnetic form factors in spacelike and timelike regions is presented. The main ingredients of our model are: $i)$ a Mandelstam formula for the matrix elements of the nucleon…

High Energy Physics - Phenomenology · Physics 2017-08-23 J. P. B. C. de Melo , T. Frederico , E. Pace , S. Pisano , G. Salme`

The electromagnetic form factor of a confined quark-antiquark pair is calculated within the framework of point-form relativistic quantum mechanics. The dynamics of theexchanged photon is explicitly taken into account by treating…

Nuclear Theory · Physics 2015-05-14 E. P. Biernat , W. Schweiger , K. Fuchsberger , W. H. Klink

Nonminimal substitution terms in electroweak currents are studied in effective chiral soliton models. It is found that the terms describing the structure of the pion lead to sizable effects in form factors and polarizabilities of the…

High Energy Physics - Phenomenology · Physics 2011-07-19 W. Broniowski , T. D. Cohen

In this article we address the physical basis of the deviation of hadron shapes from spherical symmetry (non-spherical amplitudes) with focus on the nucleon and $\Delta$. An overview of both the experimental methods and results and the…

High Energy Physics - Phenomenology · Physics 2009-01-06 A. M. Bernstein , C. N. Papanicolas

A behavior of the nucleon structure functions in the resonance region is investigated. Expressions for resonance production form factors, dependent on photon virtuality $Q^2$, which have correct threshold behavior and take into account…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Davidovsky , B. V. Struminsky

We examine the nucleon's electromagnetic form factors in a Poincare-covariant Faddeev framework. The three-quark core contributions to the form factors are obtained by employing a quark-diquark approximation. We implement the…

High Energy Physics - Phenomenology · Physics 2015-05-20 G. Eichmann , R. Alkofer , C. S. Fischer , A. Krassnigg , D. Nicmorus

I give a brief overview of experimental studies of the spectrum and the structure of the excited states of the nucleon and what we learn about their internal structure. The focus is on the effort to obtain a more complete picture of the…

Nuclear Experiment · Physics 2018-05-09 Volker D. Burkert

The electric-charge, and magnetic-dipole form factors of the proton are calculated from an underlying constituent quark picture of hadron structure based on a potential shaped after a cotangent function, which has the properties of being…

High Energy Physics - Phenomenology · Physics 2018-10-24 M. Kirchbach , C. B. Compean

The charge form factor and weak decay constant of the pion as well as the pion-quark coupling constant in symmetric nuclear matter are explored in the framework of the Nambu--Jona-Lasinio model, where the pion is described as a bound state…

Nuclear Theory · Physics 2019-01-16 Parada T. P. Hutauruk , Yongseok Oh , K. Tsushima

The quantitative knowledge of heavy nuclei's partonic structure is currently limited to rather large values of momentum fraction $x$ -- robust experimental constraints below $x \sim 10^{-2}$ at low resolution scale $Q^2$ are particularly…

Nuclear Experiment · Physics 2017-12-13 E. C. Aschenauer , S. Fazio , M. A. C. Lamont , H. Paukkunen , Pia Zurita

The strangeness content of nucleon form factors is analyzed in a two-component model with a quark-like intrinsic structure surrounded by a meson cloud. A comparison with the available experimental data from the SAMPLE, PVA4, HAPPEX and G0…

Nuclear Theory · Physics 2008-11-26 R. Bijker

We study the effects of the | qqq q\bar{q} > component of the hadronic wave function on the description of the electromagnetic structure of the nucleon. Starting with a qqq baryonic wave function which describes the baryonic and mesonic low…

Nuclear Theory · Physics 2009-11-07 F. Cano , B. Desplanques , P. González , S. Noguera

We present results for the nucleon electromagnetic form factors using an ensemble of maximally twisted mass clover-improved fermions with pion mass of about 130 MeV. We use multiple sink-source separations and three analysis methods to…

Moments of unpolarized, helicity, and transversity distributions, electromagnetic form factors, and generalized form factors of the nucleon are presented from a preliminary analysis of lattice results using pion masses down to 359 MeV. The…

High Energy Physics - Lattice · Physics 2014-11-17 R. G. Edwards , G. Fleming , Ph. Hagler , J. W. Negele , K. Orginos , A. V. Pochinsky , D. B. Renner , D. G. Richards , W. Schroers

It is widely discussed in the literature that the wave function of the nucleon bound in a nucleus is modified due to the interaction with the surrounding medium. We argue that the modification should strongly depend on the momentum of the…

Nuclear Theory · Physics 2008-11-26 C. Ciofi degli Atti , L. L. Frankfurt , L. P. Kaptari , M. I. Strikman

The structure and electroweak properties of the pion in symmetric nuclear matter are presented in the framework of the Nambu--Jona-Lasinio model. The pion is described as a bound state of a dressed quark-antiquark pair governed by the…

Nuclear Theory · Physics 2020-01-08 Parada. T. P. Hutauruk , Yongseok Oh , K. Tsushima

The electromagnetic pion production reactions are investigated within the dynamical coupled-channels model developed in {\bf Physics Reports, 439, 193 (2007)}. The meson-baryon channels included in this study are $\gamma N$, $\pi N$, $\eta…

Nuclear Theory · Physics 2008-11-26 B. Julia-Diaz , T. -S. H. Lee , A. Matsuyama , T. Sato , L. C. Smith

Precise knowledge of the nucleon's axial-current form factors is crucial for modeling GeV-scale neutrino-nucleus interactions. Unfortunately, the axial form factor remains insufficiently constrained to meet the precision requirements of…

Nuclear Theory · Physics 2020-11-04 Xilin Zhang , T. J. Hobbs , Gerald A. Miller