相关论文: Nucleon Spin-Polarisabilities from Polarisation Ob…
Model independent expressions for all polarization observables in $\mu+p\to \mu+p$ elastic scattering are obtained, taking into account the lepton mass and including the two-photon exchange contribution. The spin structure of the matrix…
The understanding of few-nucleon systems at low energies is essential, e.g. for accurate predictions of element abundances in big-bang and stellar fusion. Novel effective field theories, taking only nucleons, or nucleons and pions as…
Differential cross sections for quasi-free Compton scattering from the proton and neutron bound in the deuteron have been measured using the Glasgow/Mainz tagging spectrometer at the Mainz MAMI accelerator together with the Mainz 48 cm…
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…
The general spin structure of the matrix element, taking into account the two--photon exchange contribution, for the elastic electron (positron) --deuteron scattering has been derived using general symmetry properties of the hadron…
Below pion threshold virtual Compton scattering off the nucleon gives access to the generalized electromagnetic polarizabilities. Different theoretical results for the generalized polarizabilities have been compared. In particular, the…
The relativistic effect on differential cross sections, nucleon-to-nucleon and nucleon-to-deuteron polarization transfer coefficients, and the spin correlation function, of nucleon-deuteron elastic scattering is investigated employing…
The differential cross section and polarization observables for the elastic reaction induced by deuteron scattering off electrons at rest are calculated in the one-photon-exchange (Born) approximation. Specific attention is given to the…
I give a summary of recent results on nucleon polarizabilities, with emphasis on chiral perturbation theory. The predictive calculations of Compton scattering off the nucleon are compared to recent empirical determinations and lattice QCD…
We examine the results of Chiral Effective Field Theory ($\chi$EFT) for the scalar- and spin-dipole polarisabilities of the proton and neutron, both for the physical pion mass and as a function of $m_\pi$. This provides chiral…
Spin observables in radiative neutron capture on a proton and its inverse process, photodisintegration of the deuteron are calculated using a pionless effective field theory with di-baryon fields. Good agreement with the results of existing…
Deuteron Compton scattering below pion photoproduction threshold is considered in the framework of the non-relativistic diagrammatic approach with the Bonn OBE potential. The complete gauge-invariant set of diagrams is taken into account…
The status of Compton scattering by the nucleon at energies of the first and second resonance is summarized. In addition to a general test of dispersion theories and a precise determination of polarizabilities, the validities of four…
We present a fit of the spin-independent electromagnetic polarisabilities of the proton to low-energy Compton scattering data in the framework of covariant baryon chiral effective field theory. Using the Baldin sum rule to constrain their…
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…
We study Compton scattering in systems with A=1 and 2 using chiral perturbation theory up to fourth order. For the proton we fit the two undetermined parameters in the O(Q^4) $\gamma$p amplitude of McGovern to experimental data in the…
Expressions for the unpolarized differential cross section and for various polarization observables in the lepton-deuteron elastic scattering, $\ell+D\to \ell+D$, $\ell=e$, $\mu$, $\tau$, have been obtained in one-photon-exchange…
We discuss the application of an effective field theory (EFT) which incorporates the chiral symmetry of QCD to Compton scattering from the proton and deuteron. We describe the chiral EFT analysis of the proton Compton scattering database…
Virtual Compton scattering off nucleons and pions at low energies is discussed. Predictions for the generalized polarizabilities of the nucleon are presented within the framework of heavy-baryon chiral perturbation theory and the linear…
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…