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Related papers: Pion cloud effects on baryon masses

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Poincare' covariant Faddeev equations for the nucleon and Delta are solved to illustrate that an internally consistent description in terms of confined-quark and nonpointlike confined-diquark-correlations can be obtained. pi N-loop induced…

Nuclear Theory · Physics 2010-02-17 M. B. Hecht , M. Oettel , C. D. Roberts , S. M. Schmidt , P. C. Tandy , A. W. Thomas

The pion cloud is important in nuclear physics and in a variety of low-energy hadronic phenomena. We argue that it is natural to expect it to also be important in lepton-proton deep inelastic scattering and Drell-Yan studies of proton…

Nuclear Theory · Physics 2022-07-12 Mary Alberg , Lucas Ehinger , Gerald A. Miller

We calculate the complete $T$ matrices with decuplet contributions for pion-nucleon scattering to order $\mathcal{O}(\epsilon^3)$ in heavy baryon SU(3) chiral perturbation theory. The baryon mass in the chiral limit $M_0$ and the low-energy…

Nuclear Theory · Physics 2024-12-12 Jing Ou-Yang , Bo-Lin Huang

We analyze the octet baryon masses and the pion--nucleon $\sigma$--term in the framework of heavy baryon chiral perturbation theory. In contrast to previous investigations, we include {\it all} terms up-to-and-including quadratic order in…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. Borasoy , Ulf-G. Meißner

I briefly summarize the application of the Dyson-Schwinger/Faddeev approach to baryon form factors. Recent results for nucleon electromagnetic and axial form factors as well as N-Delta-Gamma electromagnetic transition form factors are…

High Energy Physics - Phenomenology · Physics 2011-12-22 Gernot Eichmann

The electromagnetic and gravitational form factors of the nucleon are studied simultaneously using a covariant quark-diquark approach, and the pion cloud effect on the form factors is explicitly discussed. In this study, the electromagnetic…

High Energy Physics - Phenomenology · Physics 2025-08-14 Jiaqi Wang , Dongyan Fu , Yubing Dong

We study the octet to decuplet baryon electromagnetic transitions using the covariant spectator quark model, and predict the transition magnetic dipole form factors for those involving the strange baryons. Utilizing SU(3) symmetry, the…

High Energy Physics - Phenomenology · Physics 2013-06-06 G. Ramalho , K. Tsushima

We examine the effect of adding pion exchange between quarks and pion self-energy corrections to the Los Alamos Relativistic Quark model with a short distance cutoff of the Bethe form. The contributions to the nucleon and the Delta-baryon…

Nuclear Theory · Physics 2008-11-26 T. Goldman , R. R. Silbar

The results for the elastic nucleon form factors and the electromagnetic transition amplitudes to the Delta(1232) resonance, obtained with the Hypercentral Constituent Quark Model with the inclusion of a meson cloud correction are briefly…

Nuclear Theory · Physics 2008-11-26 D. Y. Chen , Y. B. Dong , M. M. Giannini , E. Santopinto

A quark-model framework for studying nuclear medium effects on nucleon resonances is described and applied here to pion photoproduction on the deuteron, which is the simplest composite nucleon system and serves as a first test case. Pion…

Nuclear Theory · Physics 2009-11-10 Q. Zhao , J. S. Al-Khalili , R. C. Johnson

We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz…

High Energy Physics - Phenomenology · Physics 2016-05-25 De-Liang Yao , D. Siemens , V. Bernard , E. Epelbaum , A. M. Gasparyan , J. Gegelia , H. Krebs , Ulf-G. Meißner

A covariant spectator constituent quark model is applied to study the gamma N -> Delta(1600) transition. Two processes are important in the transition: a photon couples to the individual quarks of the Delta(1600) core (quark core), and a…

High Energy Physics - Phenomenology · Physics 2014-11-21 G. Ramalho , K. Tsushima

We apply the perturbative chiral quark model (PCQM) to analyse low-energy nucleon properties: electromagnetic form factors, meson-nucleon sigma-terms and pion-nucleon scattering. Baryons are described as bound states of valence quarks…

High Energy Physics - Phenomenology · Physics 2017-08-23 V. E. Lyubovitskij , Th. Gutsche , Amand Faessler

We explore the meson cloud contribution to nucleon electromagnetic form factors in dispersion relation approach. In our calculations, experimental data on transition amplitudes for pion-nucleon scatterings are taken directly as inputs, with…

High Energy Physics - Phenomenology · Physics 2024-09-27 Ek-ong Atthaphan , Attaphon Kaewsnod , Kai Xu , Moh Moh Aung , Warintorn Sreethawong , Ayut Limphirat , Yupeng Yan

Established results for the quark propagator in Landau gauge QCD, together with a detailed comparison to lattice data, are used to formulate a Poincare covariant Faddeev approach to the nucleon. The resultant three-quark amplitudes describe…

High Energy Physics - Phenomenology · Physics 2009-12-15 G. Eichmann , A. Krassnigg , M. Schwinzerl , R. Alkofer

The pion cloud renormalises the light-cone wavefunction of the nucleon which is measured in hard, exclusive photon-nucleon reactions. We discuss the leading twist contributions to high-energy exclusive reactions taking into account both the…

High Energy Physics - Phenomenology · Physics 2010-11-19 S. D. Bass , D. Schütte

Using SU(3) symmetry to constrain the pion BB' couplings, assuming SU(3) breaking comes only from one-loop pion cloud contributions, and using the the covariant spectator theory to describe the photon coupling to the quark core, we show how…

High Energy Physics - Phenomenology · Physics 2014-11-20 Franz Gross , G. Ramalho , K. Tsushima

We report on ongoing work to determine the pion-cloud contribution to the electromagnetic $N\rightarrow\Delta$ transition form factors. The starting point is an $SU(6)$ spin-flavor symmetric constituent-quark model with instantaneous…

Nuclear Theory · Physics 2019-01-30 Ju-Hyun Jung , Wolfgang Schweiger , Elmar P. Biernat

We study ground states and excitations of light octet and decuplet baryons within the framework of Dyson-Schwinger and Faddeev equations. We improve upon similar approaches by explicitly taking into account the momentum-dependent dynamics…

High Energy Physics - Phenomenology · Physics 2016-12-07 Gernot Eichmann , Christian S. Fischer , Helios Sanchis-Alepuz

A synopsis exemplifying the employment of Dyson-Schwinger equations in the calculation and explanation of hadron electromagnetic form factors and related phenomena. In particular the contribution: presents the pion form factor computed…

Nuclear Theory · Physics 2009-02-19 I. C. Cloet , C. D. Roberts