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Related papers: Higher order forward spin polarizability

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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

The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to measure the nucleon spin polarizabilities is through polarized Compton scattering.…

We calculate the forward spin-dependent photon-nucleon Compton amplitude as a function of photon energy at the next-to-leading (${\cal O}(p^4)$) order in chiral perturbation theory, from which we extract the contribution to nucleon spin…

High Energy Physics - Phenomenology · Physics 2009-10-31 Xiangdong Ji , Chung-Wen Kao , Jonathan Osborne

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

As guideline for forthcoming experiments, we present predictions from Chiral Effective Field Theory for polarized cross sections in low energy Compton scattering for photon energies below 170 MeV, both on the proton and on the neutron.…

Nuclear Theory · Physics 2009-11-10 Robert P. Hildebrandt , Harald W. Griesshammer , Thomas R. Hemmert

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

Polarized Compton scattering off the proton is studied within the framework of subtracted dispersion relations for photon energies up to 300 MeV. As a guideline for forthcoming experiments, we focus the attention on the role of the proton's…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Pasquini , D. Drechsel , M. Vanderhaeghen

We investigate the dependence of polarisation observables in elastic deuteron Compton scattering below the pion production threshold on the spin-independent and spin-dependent iso-scalar dipole polarisabilities of the nucleon. The…

Nuclear Theory · Physics 2012-03-28 Harald W. Griesshammer , Deepshikha Shukla

Compton scattering results are used to probe proton structure via measurement of higher order polarizabilities. Values for $\alpha_{E2}^p,\beta_{E2}^p,\alpha_{E\nu}^p,$ $\beta_{E\nu}^p$ determined via dispersion relations are compared to…

High Energy Physics - Phenomenology · Physics 2016-09-06 Barry R. Holstein , D. Drechsel , B. Pasquini , M. Vanderhaeghen

We present a calculation of the fourth-order (NLO) contribution to spin-dependent Compton scattering in heavy-baryon chiral perturbation theory, and we give results for the four spin polarisabilities. No low-energy constants, except for the…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. B. Vijaya Kumar , Judith A. McGovern , Michael C. Birse

Some open topics in the field of low energy photon-nucleon interactions are discussed--which in my opinion are of interest both for obtaining new information on nucleon structure as well as for precision tests of our theoretical…

Nuclear Theory · Physics 2007-05-23 Thomas R. Hemmert

We present the first attempt to extract the scalar dipole dynamical polarizabilities from proton real Compton scattering data below pion-production threshold. The theoretical framework combines dispersion relations technique, low-energy…

High Energy Physics - Phenomenology · Physics 2018-07-25 B. Pasquini , P. Pedroni , S. Sconfietti

We present a calculation of the fourth-order (NLO) contribution to spin-dependent Compton scattering in heavy-baryon chiral perturbation theory, and we give results for the four spin polarisabilities. These results have been presented…

Nuclear Theory · Physics 2017-08-23 Judith A. McGovern , Michael C. Birse , K. B. Vijaya Kumar

We analyze polarized Compton scattering which provides information on the spin-structure of the nucleon. For scattering processes with photon energies up to 100 MeV the spin-structure dependence can be encoded into four independent…

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

We present an analysis of $13$ observables in Compton scattering on the proton. Cross sections, asymmetries with polarised beam and/or targets, and polarisation-transfer observables are investigated for energies up to the $\Delta(1232)$…

Nuclear Theory · Physics 2018-04-04 Harald W. Griesshammer , Judith A. McGovern , Daniel R. Phillips

We evaluate the forward Compton scattering off the proton, based on Kramers-Kronig kind of relations which express the Compton amplitudes in terms of integrals of total photoabsorption cross sections. We obtain two distinct fits to the…

Nuclear Theory · Physics 2015-10-28 Oleksii Gryniuk , Franziska Hagelstein , Vladimir Pascalutsa

We present a formalism to extract the dynamical nucleon polarisabilities defined via a multipole expansion of the structure amplitudes in nucleon Compton scattering. In contradistinction to the static polarisabilities, dynamical…

Nuclear Theory · Physics 2009-11-07 Harald W. Griesshammer , Thomas R. Hemmert

Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. Pasquini , D. Drechsel , S. Scherer

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

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
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