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Related papers: Aspects of Nucleon Compton Scattering

200 papers

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 formulate a new power-counting scheme for a chiral effective field theory of nucleons, pions, and Deltas. This extends chiral perturbation theory into the Delta-resonance region. We calculate nucleon Compton scattering up to…

Nuclear Theory · Physics 2016-09-08 Vladimir Pascalutsa , Daniel R. Phillips

Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\gamma < 800 MeV and photon scattering angles 30^0 < \theta^{lab}_\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and…

In this sketch, I focus on Physics and formalism behind dynamical polarisabilities, a new tool to test and interpret quantitative predictions about the low-energy degrees of freedom inside the nucleon from the multipoles of Compton…

Nuclear Theory · Physics 2007-05-23 Harald W. Griesshammer

Fixed-$t$ subtracted dispersion relations are presented for Compton scattering off the nucleon at energies $E_\gamma \leq 500$ MeV, as a formalism to extract the nucleon polarizabilities from the data with a minimum of model dependence. The…

High Energy Physics - Phenomenology · Physics 2011-04-15 M. Gorchtein , D. Drechsel , B. Pasquini , M. Vanderhaeghen

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

We investigate the spin-independent part of the virtual Compton scattering (VCS) amplitude off the nucleon within the framework of chiral perturbation theory. We perform a consistent calculation to third order in external momenta according…

Nuclear Theory · Physics 2009-10-30 Thomas R. Hemmert , Barry R. Holstein , Germar Knoechlein , Stefan Scherer

We calculate the nucleons' electromagnetic polarizabilities in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction of the electric polarizabilities for the neutron and the proton are…

High Energy Physics - Phenomenology · Physics 2016-08-14 Véronique Bernard , Norbert Kaiser , Armin Schmidt , Ulf-G. Meißner

Theory and prospects of Compton scattering on nucleons and light nuclei below 500 MeV are outlined; cf. Refs. [1-3]. Invited contribution at the Workshop to Explore Physics Opportunities with Intense, Polarized Electron Beams with Energy up…

Nuclear Theory · Physics 2015-06-16 Harald W. Griesshammer , Daniel R. Phillips , Judith A. McGovern

Chiral effective field theories have a long history studying the process of Compton scattering on the nucleon. In this contribution I want to focus on the new developments that have occured since the last Chiral Dynamics conference in Mainz…

Nuclear Theory · Physics 2017-08-23 Thomas R. Hemmert

We outline a microscopic framework to calculate nucleon Compton scattering from the level of quarks and gluons within the covariant Faddeev approach. We explain the connection with hadronic expansions of the Compton scattering amplitude and…

High Energy Physics - Phenomenology · Physics 2016-03-23 Gernot Eichmann

Polarized Compton scattering on the deuteron is studied in nuclear effective field theory. A set of tensor structures is introduced to define 12 independent Compton amplitudes. The scalar and vector amplitudes are calculated up to ${\cal…

Nuclear Theory · Physics 2009-11-10 Jiunn-Wei Chen , Xiangdong Ji , Yingchuan Li

A status report on the topic Compton scattering and polarizabilities is presented with emphasis on the scalar t-channel as entering into dispersion theory. Precise values for the polarizabilities are obtained leading to $\alpha_p = 12.0\pm…

High Energy Physics - Phenomenology · Physics 2013-06-26 Martin Schumacher , Michael D. Scadron

These proceedings sketch how combining recent theoretical advances with data from the new generation of high-precision Compton scattering experiments on both the proton and few-nucleon systems offers fresh, detailed insight into the Physics…

Nuclear Theory · Physics 2009-11-10 Harald W. Griesshammer

We present recent results on elastic deuteron Compton scattering calculations for polarised beans and targets up to next-to-leading order within Chiral Effective Field Theory in the Small Scale Expansion variant to implement a dynamical…

Nuclear Theory · Physics 2014-11-20 Harald W. Griesshammer , Deepshikha Shukla

We calculate the spin-polarizabilities of the nucleon by means of dispersion relation, where the pion photoproduction amplitude predicted by chiral soliton model is utilized. We consider the $N\pi$ and $\Delta\pi$ channels in the…

Nuclear Theory · Physics 2009-10-31 Y. Tanushi , S. Saito , M. Uehara

We present a calculation of the virtual Compton scattering amplitude for the pseudoscalar meson octet in the framework of chiral perturbation theory at ${\cal O}(p^4)$. We calculate the electromagnetic generalized polarizabilities and…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. Fuchs , B. Pasquini , C. Unkmeir , S. Scherer

We discuss a recent computation of Compton scattering on the deuteron at photon energies of order the pion mass. An interaction kernel is computed in baryon chiral perturbation theory and sewn to phenomenological deuteron wave functions. As…

Nuclear Theory · Physics 2007-05-23 Silas R. Beane

In addition to the E2/M1 ratio of the N->$\Delta$ transition, the electromagnetic polarizabilities and spin-polarizabilities are important structure constants of the nucleon which serve as sensitive tests of chiral perturbation theory and…

Nuclear Experiment · Physics 2017-08-23 Martin Schumacher

The spin structure of the nucleon is analyzed in the framework of a Lorentz-invariant formulation of baryon chiral perturbation theory. The structure functions of doubly virtual Compton scattering are calculated to one-loop accuracy (fourth…

High Energy Physics - Phenomenology · Physics 2009-11-07 Véronique Bernard , Thomas R. Hemmert , Ulf-G. Meißner