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Related papers: Low Energy Compton Scattering and Nucleon Structur…

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Two different topics relevant for DA$\Phi$NE and CEBAF, respectively, are covered. First we analyze the rare radiative eta decay mode $\eta\to\pi\pi\gamma\gamma$ within the framework of chiral perturbation theory at ${\cal O}(p^4)$. We then…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Scherer

We calculate the $N^*$ contributions to the generalized polarizabilities of the proton in virtual Compton scattering. The following nucleon excitations are included: $N^*(1535)$, $N^*(1650)$, $N^*(1520)$, $N^*(1700)$, $\Delta(1232)$,…

Nuclear Theory · Physics 2015-06-26 G. Q. Liu , A. W. Thomas , P. A. M. Guichon

We present a calculation of the virtual Compton scattering amplitude for $\gamma^\ast+\pi\to \gamma+\pi$ in the framework of chiral perturbation theory at ${\cal O}(p^4)$. We explicitly derive expressions for generalized electromagnetic…

High Energy Physics - Phenomenology · Physics 2009-10-31 C. Unkmeir , S. Scherer , A. I. L'vov , D. Drechsel

We review theoretical progress and prospects for determining the nucleon's static dipole polarisabilities from Compton scattering on few-nucleon targets, including new values; see Refs. [1-5] for details and a more thorough bibliography.

Nuclear Theory · Physics 2016-12-12 Harald W. Griesshammer , Judith A. McGovern , Daniel R. Phillips

The forward doubly-virtual Compton scattering (VVCS) off the nucleon contains a wealth of information on nucleon structure, relevant to the calculation of the two-photon-exchange effects in atomic spectroscopy and electron scattering. We…

High Energy Physics - Phenomenology · Physics 2020-07-15 Jose Manuel Alarcón , Franziska Hagelstein , Vadim Lensky , Vladimir Pascalutsa

A forward dispersion calculation is implemented for the spin polarizabilities $\gamma_1, ... ,\gamma_4$ of the proton and the neutron. These polarizabilities are related to the spin structure of the nucleon at low energies and are…

Nuclear Theory · Physics 2009-10-30 D. Drechsel , G. Krein , O. Hanstein

Virtual Compton scattering on the proton has been investigated at three yet unexplored values of the four-momentum transfer $Q^2$: 0.10, 0.20 and 0.45 GeV$^2$, at the Mainz Microtron. Fits performed using either the low-energy theorem or…

I review recent progress made in the calculation of nucleon properties in the framework of heavy baryon CHPT. Topics include: Compton scattering, $\pi N$ scattering, the anatomy of a low-energy constant and the induced pseudoscalar form…

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

We consider the spin-averaged nucleon forward Compton scattering amplitude in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction for the spin-averaged forward Compton scattering…

High Energy Physics - Phenomenology · Physics 2015-06-25 V. Bernard , N. Kaiser , Ulf-G. Meißner , A. Schmidt

We review the current state of knowledge of the nucleon polarizabilities and of their role in nucleon Compton scattering and in hydrogen spectrum. We discuss the basic concepts, the recent lattice QCD calculations and advances in chiral…

Nuclear Theory · Physics 2016-03-23 Franziska Hagelstein , Rory Miskimen , Vladimir Pascalutsa

A microscopic calculation of Compton scattering on the nucleon is presented which encompasses the lowest energies -- yielding nucleon polarizabilities -- and extends to energies of the order of 600 MeV. We have used the covariant "Dressed…

Nuclear Theory · Physics 2009-11-07 S. Kondratyuk , O. Scholten

An effective field theory is used to give a model-independent description of Compton scattering at energies comparable to the pion mass. The amplitudes for scattering on the proton and the deuteron, calculated to fourth order in small…

Nuclear Theory · Physics 2008-11-26 S. R. Beane , M. Malheiro , J. A. McGovern , D. R. Phillips , U. van Kolck

We propose to conduct a measurement of the Virtual Compton Scattering reaction in Hall C that will allow the precise extraction of the two scalar Generalized Polarizabilities (GPs) of the proton in the region of $Q^2=0.05~(GeV/c)^2$ to…

Virtual Compton scattering off the nucleon has been studied in the one-loop approximation of the linear sigma model. The three generalized polarizabilities of the nucleon have been calculated and compared with the existing theoretical…

Nuclear Theory · Physics 2007-05-23 A. Metz , D. Drechsel

Proton Compton scattering is analyzed with the chiral Lagrangian. Partial-wave amplitudes are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by…

High Energy Physics - Phenomenology · Physics 2011-08-25 A. M. Gasparyan , M. F. M. Lutz , B. Pasquini

A review is given of the very recent developments in the fields of real and virtual Compton scattering off the nucleon. Both real and virtual Compton scattering reactions are discussed at low outgoing photon energy where one accesses…

High Energy Physics - Phenomenology · Physics 2016-09-06 Marc Vanderhaeghen

A calculation of deuteron Compton scattering using non-relativistic perturbation theory is presented,with the primary motivation of investigating the feasibility of determining the neutron polarizabilities from this type of experiment. This…

Nuclear Theory · Physics 2009-10-31 Jonathan J. Karakowski , Gerald A. Miller

Virtual Compton Scattering is studied at the Thomas Jefferson National Accelerator Facility in the energy domain below pion threshold and in the Delta(1232) resonance region. The data analysis is based on the Dispersion Relation (DR)…

High Energy Physics - Phenomenology · Physics 2007-05-23 The Jefferson Lab Hall A Collaboration , G. Laveissiere

We discuss the virtual Compton scattering amplitude $\gamma^\ast+\pi\to \gamma+\pi$ which enters the reaction $\pi^-+e^-\to\pi^-+e^-+\gamma$. The low-energy scattering amplitude is divided into a model-independent part, involving only the…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Scherer

Compton scattering processes are ideal to study electric and magnetic dipole polarizabilities of nucleons. These fundamental quantities parametrize the responses of the internal degrees of freedoms to a monochromatic photon probe. In this…

Nuclear Theory · Physics 2016-12-23 Berhan Demissie , Harald W. Grießhammer