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Related papers: Non-perturbative structure of the nucleon

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We extend our previous study of elastic pion-nucleon scattering in the framework of chiral perturbation theory by performing a combined analysis of the reactions $\pi N \to \pi N$ and $\pi N \to \pi \pi N$. The calculation is carried out to…

Nuclear Theory · Physics 2020-03-05 D. Siemens , V. Bernard , E. Epelbaum , A. M. Gasparyan , H. Krebs , Ulf-G. Meißner

We investigate isospin breaking in low-energy pion-nucleon scattering in the framework of chiral perturbation theory. This work extends the systematic analysis of [1] to the energy range above threshold. Various relations, which identically…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner

Peripheral nucleon-nucleon scattering is analysed in the framework of an effective field theory. Distorted-wave methods are used to remove the effects of one-pion exchange. Two-pion exchange and recoil corrections to one-pion exchange are…

Nuclear Theory · Physics 2009-11-10 Michael C. Birse , Judith A. McGovern

We will give a short introduction to the one-nucleon sector of chiral perturbation theory and will address the issue of a consistent power counting and renormalization. We will discuss the infrared regularization and the extended…

Nuclear Theory · Physics 2008-11-26 Stefan Scherer

The standard way to demonstrate the relevance of chiral symmetry for the NN interaction is to consider higher partial waves of NN scattering which are controlled entirely by chiral pion-exchanges (since contacts vanish). However, in…

Nuclear Theory · Physics 2021-01-19 H. Alanazi , R. Machleidt

Heavy baryon chiral perturbation theory is applied to one- and two nucleon processes.

Nuclear Theory · Physics 2015-05-18 F. Myhrer

We analyse elastic-pion nucleon scattering to fourth order in heavy baryon chiral perturbation theory, extending the third order study published in Nucl. Phys. A640 (1998) 199. We use various partial wave analyses to pin down the low-energy…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner

We investigate threshold pion photoproduction in the framework of heavy baryon chiral perturbation theory. We give the expansion of the electric dipole amplitude $E_{0+}$ to three orders in $\mu$, the ratio of the pion to nucleon mass, and…

High Energy Physics - Phenomenology · Physics 2009-09-25 V. Bernard , N. Kaiser , Ulf-G. Meißner

We construct the complete effective chiral pion-nucleon Lagrangian to third order in small momenta based on relativistic chiral perturbation theory. We then perform the so-called heavy baryon limit and construct all terms…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nadia Fettes , Ulf-G. Meißner , Sven Steininger

I give a taste of recent progress in using chiral perturbation theory to understand nucleon and deuteron structure.

Nuclear Theory · Physics 2017-08-23 Silas R. Beane

Chiral perturbation theory (ChPT) is the effective field theory of the strong interactions at low energies. We will address the issue of a consistent power counting scheme in a manifestly Lorentz-invariant formulation of baryon ChPT. As…

High Energy Physics - Phenomenology · Physics 2009-01-08 Stefan Scherer

Electroproduction of pions on the nucleon near the threshold is analyzed within the framework of baryon chiral perturbation theory. We give a thorough discussion of the low--energy theorems related to charged and neutral…

High Energy Physics - Phenomenology · Physics 2016-09-01 V. Bernard , N. Kaiser , T. -S. H. Lee , Ulf-G. Meißner

Next to leading order effective field theory calculations are performed for $ {}^1S_0$ NN scattering using subtractive renormalization procedure. One pion exchange and contact interaction potentials are iterated using Lippman-Schwinger…

Nuclear Theory · Physics 2009-10-31 J. Gegelia

We study pion--nucleon scattering with a chiral lagrangian of pions, nucleons, and $\Delta$-isobars to order $Q^3$, where $Q$ is a generic small momentum. We compare the results from heavy baryon chiral perturbation theory with those from…

Nuclear Theory · Physics 2009-11-07 Kenichi Torikoshi , Paul J. Ellis

We study the production amplitude for the reaction $NN\to NN\pi$ up to next-to-leading order in chiral perturbation theory. We show that the irreducible chiral loops at this order exactly cancel those terms that arise from the off-shell…

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

I review recent progress made in the description of pion-nucleon scattering, the $\sigma$--term, the scalar form factor and the strangeness content of the nucleon in the framework of heavy baryon chiral perturbation theory. Other topics are…

High Energy Physics - Phenomenology · Physics 2011-04-15 Ulf-G. Meißner

A chiral quark-model approach is adopted to study the $\gamma p\rightarrow \pi^0p$ and $\gamma n\rightarrow \pi^0 n$ reactions. Good descriptions of the total and differential cross sections and single-polarization observables are obtained…

Nuclear Theory · Physics 2015-12-18 Li-Ye Xiao , Xu Cao , Xian-Hui Zhong

We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…

Nuclear Theory · Physics 2021-08-04 N. Rijneveen , A. M. Gasparyan , H. Krebs , E. Epelbaum

We present a new chiral expansion scheme for the nucleon-nucleon scattering amplitude which preserves unitarity exactly. Our effective field theory builds on the power counting rules for 2-nucleon reducible diagrams proposed in \cite{lutz}.…

Nuclear Theory · Physics 2010-12-16 M. Lutz

We show how the unitarized description of pion nucleon scattering within Heavy Baryon Chiral Perturbation Theory can be considerably improved, by a suitable reordering of the expansion over the nucleon mass. Within this framework, the…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Gómez Nicola , J. Nieves , J. R. Peláez , E. Ruiz Arriola