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Related papers: Non-perturbative structure of the nucleon

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A complete calculation of the corrections to pion-deuteron scattering length up to order $\chi^{3/2}$ with $\chi=m_{\pi}/M_{N}$ is performed. The calculation includes the dispersive contributions and corrections due to the explicit…

Nuclear Theory · Physics 2008-11-26 V. Baru , J. Haidenbauer , C. Hanhart , A. Kudryavtsev , V. Lensky , U. -G. Meissner

The status of chiral perturbation theory in the meson sector is reviewed. The main emphasis is on recent developments in pion pion scattering, in semileptonic decays and in nonleptonic kaon decays. A few other selected topics are also…

High Energy Physics - Phenomenology · Physics 2009-06-25 Gerhard Ecker

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 construct a low-energy effective field theory which allows the full treatment of isospin-breaking effects in semileptonic weak interactions. To this end, we enlarge the particle spectrum of chiral perturbation theory with virtual photons…

High Energy Physics - Phenomenology · Physics 2011-08-17 M. Knecht , H. Neufeld , H. Rupertsberger , P. Talavera

We consider pion-nucleon scattering in heavy-baryon chiral perturbation theory to third order. All electromagnetic corrections appearing to this order are included. We thus have a consistent description of strong and electromagnetic…

High Energy Physics - Phenomenology · Physics 2009-11-07 Nadia Fettes , Ulf-G. Meißner

We review the structure of Roy-Steiner equations for pion-nucleon scattering, the solution for the partial waves of the t-channel process $\pi\pi\to \bar N N$, as well as the high-accuracy extraction of the pion-nucleon S-wave scattering…

High Energy Physics - Phenomenology · Physics 2016-03-24 Martin Hoferichter , Jacobo Ruiz de Elvira , Bastian Kubis , Ulf-G. Meißner

In the first part of these lectures, I consider chiral perturbation theory in the presence of matter fields. It allows to systematically work out the consequences of the broken chiral symmetry of QCD. As examples, threshold pion photo- and…

High Energy Physics - Phenomenology · Physics 2015-06-25 Ulf-G. Meißner

Chiral symmetry serves as a guiding principle in low-energy hadron dynamics. An effective lagrangian, which explicitly breaks chiral symmetry via a small mass term, allows for a systematic method of calculating higher order corrections to…

Nuclear Theory · Physics 2007-05-23 F. Myhrer

We present a new rearrangement of short-range interactions in the $^1S_0$ nucleon-nucleon channel within Chiral Effective Field Theory. This is intended to reproduce the amplitude zero (scattering momentum $\simeq$ 340 MeV) at leading…

Nuclear Theory · Physics 2018-02-14 M. Sánchez Sánchez , C. -J. Yang , Bingwei Long , U. van Kolck

We extend an effective Lagrangian embodying broken scale and chiral symmetry to include explicit chiral symmetry breaking and an additional chiral invariant term which allows for an axial coupling constant greater than unity. We also…

Nuclear Theory · Physics 2009-10-28 G. Carter , P. J. Ellis , S. Rudaz

Virtual Compton scattering off nucleons and pions at low energies is discussed. Predictions for the generalized polarizabilities of the nucleon are presented within the framework of heavy-baryon chiral perturbation theory and the linear…

High Energy Physics - Phenomenology · Physics 2011-04-15 S. Scherer

Pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering are analyzed within a scheme based on the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes…

High Energy Physics - Phenomenology · Physics 2011-02-11 A. M. Gasparyan , M. F. M. Lutz

We give a brief review of the theoretical description of low energy pion-pion scattering by the combined use of Chiral Perturbation Theory and Roy equations, an update of the Regge parametrization of $\pi\pi$ cross sections at high…

High Energy Physics - Phenomenology · Physics 2010-11-05 Irinel Caprini , Gilberto Colangelo , Heinrich Leutwyler

We study the perturbative renormalizability of chiral two pion exchange in nucleon-nucleon scattering for p- and d-waves within the effective field theory approach. The one pion exchange potential is fully iterated at the leading order in…

Nuclear Theory · Physics 2011-12-16 M. Pavon Valderrama

We propose a novel way to formulate Chiral Perturbation Theory in a nuclear background, characterized by a static, non-uniform distribution of the baryon number that describes the finite nucleus. In the limiting case of a uniform…

High Energy Physics - Phenomenology · Physics 2015-06-25 L. Girlanda , A. Rusetsky , W. Weise

We examine the role of the elementary isoscalar pion--nucleon scattering amplitude in the description of the processes $pp \to pp\pi^0$ and $pp\to d\pi^+$ at threshold. We argue that the presently used tree level dimension two approximation…

Nuclear Theory · Physics 2009-10-30 C. Hanhart , J. Haidenbauer , M. Hoffmann , Ulf-G. Meißner , J. Speth

We use chiral perturbation theory to investigate hadronic properties in strong electric and magnetic fields. A strong-field power counting is employed, and results for pions and nucleons are obtained using Schwinger's proper-time method. In…

High Energy Physics - Phenomenology · Physics 2008-12-18 Brian C. Tiburzi

A major goal of nuclear theory is to explain the spectra and stability of nuclei in terms of effective many-body interactions amongst the nucleus' constituents-the nucleons, i.e., protons and neutrons. Such an approach, referred to below as…

Recent attempts to detect the pion polarizability via analysis of $\gamma\gamma\rightarrow\pi\pi$ measurements are examined. The connection between calculations based on dispersion relations and on chiral perturbation theory is established…

High Energy Physics - Phenomenology · Physics 2011-07-19 John F. Donoghue , Barry R. Holstein

We show that the tail of the chiral two-pion exchange nucleon-nucleon potential is proportional to the $\pi N$ scalar form factor and discuss how it can be translated into effective scalar meson interactions. We then construct a kernel for…

Nuclear Theory · Physics 2009-11-06 C. M. Maekawa , J. C. Pupin , M. R. Robilotta