Related papers: Nucleon Polarizabilities from Low-Energy Compton S…
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…
We calculate the $T$-matrices of elastic pion-nucleon ($\pi N$) scattering up to fourth order in SU(3) heavy baryon chiral perturbation theory. The pertinent low-energy constants are determined by fitting to $\pi N$ phase shifts below 200…
The subject of nucleon polarizabilities in real, virtual, and doubly virtual Compton scattering is discussed with respect to what is known and how such quantities can be extracted from data.
We study pion-nucleon scattering at tree level with a chiral lagrangian of pions, nucleons, and $\Delta$-isobars using a K-matrix unitarization procedure. Evaluating the scattering amplitude to order $Q^2$, where $Q$ is a generic small…
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…
In the context of chiral SU(2) perturbation theory, pion-kaon scattering is analysed near the threshold to fourth chiral order. The scattering amplitude is calculated both in the relativistic framework and by using an approach similar to…
During the workshop "Compton Scattering off Protons and Light Nuclei: pinning down the nucleon polarisabilities" (ECT*, Trento, Italy, 29 July -- 2 August 2013, http://www.ectstar.eu/node/98), recent developments had been reviewed in…
A proton spin-polarizability characterizing backward Compton scattering has been extracted from a dispersion analysis of data between 33 and 309 MeV. This backward spin-polarizability, "delta" = 27.1 +/-2.2(stat+sys) +2.8/-2.4(model) in…
The Compton process with the initial states of photons and neutrons described by the density matrices of a general form is studied for low energies of photons. The coherent contribution to the inclusive probability to record a photon is…
The polarizabilities of light pseudoscalar mesons can be extracted from differential cross sections for Compton scattering near threshold. While this has been accomplished for charged pions employing Primakoff reactions, a corresponding…
As a guideline for future experiments to extract the four (leading) spin polarizabilities of the nucleon, we have constructed the forward amplitude for polarized Compton scattering by dispersion integrals. These integrals have been…
The effect of the self-energy on the photon-proton elastic scattering is investigated for the backward and the forward directions. The shape of the Thomson scattering at the photon energy $\omega \to 0$ is broken by taking into account the…
We give an overview of low-energy Compton scattering (gamma^(*) p --> gamma p) with a real or virtual incoming photon. These processes allow the investigation of one of the fundamental properties of the nucleon, i.e. how its internal…
We calculate the electric polarizability $\alpha(q^2)$ of the proton in virtual Compton scattering using the Skyrme model. The $q^2$ dependence of the polarizability is comparable with the predictions obtained from the non-relativistic…
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}.…
The S wave pion deuteron scattering length is presented at NLO in the Effective Field Theory formulation of the two nucleon system with perturbative pions. At this order, this observable is determined by the iso-scalar S wave pion nucleon…
Using the techniques of chiral effective field theories we evaluate the so called generalized polarizabilities of the nucleon, which characterize the structure dependent components in virtual Compton scattering (VCS) as probed in the…
The scattering amplitude of the pion-nucleon elastic scattering is calculated by the lowest-order approximation of the perturbative expansion with the non-perturbative term. The self-energy of nucleon is determined so as to give the…
We show how effectively effective quantum field theories work in nuclear physics. Using the physically transparent cut-off regularization, we study the simplest nuclear systems of two nucleons for both bound and scattering states at a…
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…