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Related papers: Chiral corrections to $\pi^-\gamma\to 3\pi$ proces…

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We calculate in chiral perturbation theory the dominant next-to-leading order correction to the $\pi\gamma$-exchange NN-potential proportional to the large isovector magnetic moment $\kappa_v = 4.7$ of the nucleon. The corresponding…

Nuclear Theory · Physics 2008-11-26 N. Kaiser

We evaluate the electric and magnetic polarizabilities of charged pions in the framework of chiral perturbation theory at next-to-leading order. This requires a two-loop evaluation of the Compton amplitude near threshold. We estimate the…

High Energy Physics - Phenomenology · Physics 2011-07-19 Urs Buergi

We study the pp \to pp\pi^0 reaction near threshold based on heavy-baryon chiral perturbation theory. We show that the two-pion-exchange diagrams give much larger contribution than the one-pion-exchange diagram which is of lower chiral…

Nuclear Theory · Physics 2008-11-26 F. Myhrer

The study of the charge asymmetry of produced particles allows to investigate the interference of different production mechanisms and to determine new features of the corresponding amplitudes. In the process $e^- e^+ \to e^- e^+ \pi^+…

High Energy Physics - Phenomenology · Physics 2009-01-07 I. F. Ginzburg , A. Schiller , V. G. Serbo

Elastic pion-pion and pion-nucleon scattering are reviewed in the context of chiral perturbation theory. Theoretical results from systematic low-energy expansions to O(p^6) for pion-pion and to O(p^3) for pion-nucleon scattering are…

High Energy Physics - Phenomenology · Physics 2009-10-30 Gerhard Ecker

We use chiral perturbation theory to evaluate the scattering amplitude for the process Pi^+ K^- to Pi^+ K^- at leading and next-to-leading orders in the chiral counting and in the presence of isospin breaking effects. We also discuss the…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. Nehme

The pion-pion scattering amplitudes provided by second-order chiral perturbation theory are confronted with known rigorous constraints derived from the axioms of quantum field theory. We mainly test constraints restricting the…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. Ananthanarayan , D. Toublan , G. Wanders

Consideration of the analytic properties of pion-induced baryon self energies leads to new functional forms for the extrapolation of light baryon masses. These functional forms reproduce the leading non-analytic behavior of chiral…

Nuclear Theory · Physics 2010-02-17 Anthony W. Thomas , Derek B. Leinweber , Kazuo Tsushima , Stewart V. Wright

Threshold neutral pion photoproduction on light nuclei is studied in the framework of baryon chiral perturbation theory. We obtain a general formula for the electric dipole amplitude in the special case of neutral pion photoproduction on a…

Nuclear Theory · Physics 2008-11-26 S. R. Beane , C. Y. Lee , U. van Kolck

We present and discuss a systematic calculation, based on two-loop chiral perturbation theory, of the pion-nuclear s-wave optical potential. A proper treatment of the explicit energy dependence of the off-shell pion self-energy together…

Nuclear Theory · Physics 2009-11-07 E. E. Kolomeitsev , N. Kaiser , W. Weise

We report on a novel scheme based on the chiral Lagrangian. It is used to analyze pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering. Subthreshold partial-wave amplitudes are calculated in chiral perturbation…

High Energy Physics - Phenomenology · Physics 2015-05-20 A. M. Gasparyan , M. F. M. Lutz

Near threshold pion production experiments have been recently carried out and used to extract S--wave $\pi\pi$ scattering lengths. We emphasize here that at present these processes are related only at the tree level (and its first…

High Energy Physics - Phenomenology · Physics 2014-11-17 M. G. Olsson , Ulf-G. Meißner , N. Kaiser , V. Bernard

Two-point functions related to the pion weak decay constant $f_\pi$ are calculated from the generating functional of chiral perturbation theory in the mean field approximation and the heavy-baryon limit. The aim is to demonstrate that…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. Kirchbach , A. Wirzba

We discuss the exclusive photoproduction of $\pi^{+}\pi^{-}$ pairs in photon-proton and in proton-proton collisions at high energies. The $\rho^{0}$, $\omega$, $f_{2}(1270)$, and non-resonant (Drell-S\"oding) contributions are considered.…

High Energy Physics - Phenomenology · Physics 2026-04-29 Piotr Lebiedowicz , Otto Nachtmann , Antoni Szczurek

In these notes we present an introductory review on various topics about low energy pion physics (some kaon physics is discussed as well). Among these, we include the uses of analyticity and unitarity to describe partial wave amplitudes…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. J. Yndurain

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

The relativistic amplitudes of pion photo- and electroproduction are calculated by dispersion relations at constant t. Several sum rules and low-energy theorems for the threshold amplitudes are investigated within this technique. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. Drechsel , B. Pasquini , L. Tiator

We consider multi-particle contributions to nucleon two- and three-point functions from the perspective of chiral dynamics. Lattice nucleon interpolating operators, which have definite chiral transformation properties, can be mapped into…

High Energy Physics - Lattice · Physics 2015-05-27 Brian C. Tiburzi

Lattice QCD studies of hadron-hadron interactions are performed by computing the energy levels of the system in a finite box. The shifts in energy levels proportional to inverse powers of the volume are related to scattering parameters in a…

High Energy Physics - Lattice · Physics 2014-11-17 Paulo F. Bedaque , Ikuro Sato , Andre Walker-Loud

We show that diffractive production of a single neutral pion in photon-induced reactions at high energy is dynamically suppressed due to the approximate chiral symmetry of QCD. These reactions have been proposed as a test of the odderon…

High Energy Physics - Phenomenology · Physics 2011-09-13 Carlo Ewerz , Otto Nachtmann