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Related papers: On chiral corrections to nucleon GPD

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We compute the leading non-analytic contributions of the form m_q Log(m_q) to matrix elements of twist-2 operators in the nucleon and pion using effective field theory. Previously omitted one-loop contributions that are related to…

Nuclear Theory · Physics 2014-11-18 Daniel Arndt , Martin J. Savage

Chiral corrections to the delta axial charge are determined using heavy baryon chiral perturbation theory. Knowledge of this axial coupling is necessary to assess virtual-delta contributions to nucleon and delta observables. We give isospin…

Nuclear Theory · Physics 2008-12-18 Fu-Jiun Jiang , Brian C. Tiburzi

We calculate in chiral perturbation theory the double-pion photoproduction processes $\pi^-\gamma \to \pi^- \pi^0\pi^0$ and $\pi^-\gamma\to \pi^+\pi^-\pi^-$ at low energies. At leading order these reactions are governed by the chiral…

High Energy Physics - Phenomenology · Physics 2011-03-28 N. Kaiser

We calculate shell-model matrix elements of the axial-charge exchange current operators that have been obtained up to the next-to-leading order from heavy-fermion chiral perturbation theory. It is found that loop corrections to the soft…

Nuclear Theory · Physics 2009-10-28 Tae-Sun Park , Ian S. Towner , Kuniharu Kubodera

The chiral perturbation theory (ChPT) of pions is extended to include vector mesons as well as pertinent degrees of freedom. By counting the typical momentum scale of vector mesons as order of $Q$ and vector meson masses as of the order of…

High Energy Physics - Phenomenology · Physics 2024-01-23 Tae-Sun Park

We study possible restoration patterns of chiral symmetry in a generalized hidden local symmetry model, which is a low energy effective theory of QCD including pseudo-scalar, vector and axial-vector mesons. We derive Wilsonian…

High Energy Physics - Phenomenology · Physics 2009-11-11 Yoshimasa Hidaka , Osamu Morimatsu , Munehisa Ohtani

The presence of axions introduces new diagrams at one-loop order to the two-photon decays of the neutral pion through axion-pion mixing. In this work, we calculate this correction, missing in all current calculations, in the framework of…

High Energy Physics - Phenomenology · Physics 2025-03-17 Zhen-Yan Lu , Yang Huang , Ji-Gui Cheng , Qi Lu , Shu-Peng Wang

We have performed a theoretical study of the axial Nucleon to Delta(1232) ($N\to\Delta$) transition form factors up to one-loop order in covariant baryon chiral perturbation theory within a formalism in which the unphysical spin-1/2…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. S. Geng , J. Martin Camalich , L. Alvarez-Ruso , M. J. Vicente Vacas

We analyze the moments of the isosinglet generalized parton distributions H, E, H-tilde, E-tilde of the nucleon in one-loop order of heavy-baryon chiral perturbation theory. We discuss in detail the construction of the operators in the…

High Energy Physics - Phenomenology · Physics 2020-06-19 M. Diehl , A. Manashov , A. Schafer

We calculate the pion pole term of the light-by-light contribution to the $g-2$ of the muon in the framework of an effective chiral quark model with instanton-like nonlocal quark--quark interaction. The full kinematic dependence of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexander E. Dorokhov , Wojciech Broniowski

We revisit the work of K. Goeke, M. Harvey, F. Gr\"ummer, and J. N. Urbano (Phys. Rev. {\bf D37}, 754 (1988)) who considered a chiral model for the nucleon based on the linear sigma model with scalar-isoscalar scalar-isovector mesons…

High Energy Physics - Phenomenology · Physics 2016-08-25 T. S. T. Aly , J. A. McNeil

The introduction of axions gives rise to additional one-loop diagrams for the two-photon decays of neutral pions via axion-pion mixing. We compute this correction that has been overlooked in existing calculations, within the framework of…

High Energy Physics - Phenomenology · Physics 2025-07-25 Zhen-Yan Lu , Shu-Peng Wang , Qi Lu

We discuss the nonlocal generalization of the QCD chiral anomaly along the light-cone and derive relations between twist-two, twist-three and twist-four generalized parton distributions (GPDs) mediated by the anomaly. We further establish…

High Energy Physics - Phenomenology · Physics 2024-11-12 Shohini Bhattacharya , Yoshitaka Hatta , Jakob Schoenleber

The unknown constants in Chiral Perturbation Theory needed for an all orders analysis of the polarizabilities and electromagnetic corrections to the masses of the pseudo-Goldstone bosons are estimated at leading order in $1/N_c$. We…

High Energy Physics - Phenomenology · Physics 2009-10-28 Johan Bijnens , Joaquim Prades

Near threshold neutral pion electroproduction on the deuteron is studied in the framework of heavy baryon chiral perturbation theory. We include the next-to-leading order corrections to the three-body contributions. We find an improved…

Nuclear Theory · Physics 2007-05-23 H. Krebs , V. Bernard , Ulf-G. Meißner

We present the dominant two- and three-pion-exchange contributions to the nucleon-nucleon interaction at sixth order (next-to-next-to-next-to-next-to-next-to-leading order, N5LO) of chiral perturbation theory. Phase shifts with orbital…

Nuclear Theory · Physics 2015-12-16 D. R. Entem , N. Kaiser , R. Machleidt , Y. Nosyk

We compute the light-cone momentum distributions of pions in the nucleon in chiral effective theory using both pseudovector and pseudoscalar pion-nucleon couplings. For the pseudovector coupling we identify \delta-function contributions…

High Energy Physics - Phenomenology · Physics 2013-04-03 M. Burkardt , K. S. Hendricks , Chueng-Ryong Ji , W. Melnitchouk , A. W. Thomas

Nonanalytic $m_q^{1/2}$ and $m_q\ln m_q$ chiral corrections to the baryon magnetic moments are computed. The calculation includes contributions from both intermediate octet and decuplet baryon states. Unlike the one-loop contributions to…

High Energy Physics - Phenomenology · Physics 2010-04-06 Elizabeth Jenkins , Michael Luke , Aneesh V. Manohar , M. J. Savage

We compute the one-loop contributions to spin-averaged generalized parton distributions (GPDs) in the proton from pseudoscalar mesons with intermediate octet and decuplet baryon states at nonzero skewness. Our framework is based on nonlocal…

High Energy Physics - Phenomenology · Physics 2024-10-02 Zhengyang Gao , Fangcheng He , Chueng-Ryong Ji , W. Melnitchouk , Y. Salamu , P. Wang

We explore the link between the chiral symmetry of QCD and the numerical results of the light-front quark model, analyzing both the two-point and three-point functions of the pion. Including the axial-vector coupling as well as the…

High Energy Physics - Phenomenology · Physics 2020-08-12 Ho-Meoyng Choi , Chueng-Ryong Ji