Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1836741 | Nuclear Physics A | 2010 | 57 Pages |
Abstract
We present and apply a novel scheme for studying photon- and pion-nucleon scattering beyond the threshold region. Partial-wave amplitudes for the γN and ÏN states are obtained by an analytic extrapolation of subthreshold reaction amplitudes computed in chiral perturbation theory, where the constraints set by electromagnetic-gauge invariance, causality and unitarity are used to stabilize the extrapolation. Based on the chiral Lagrangian we recover the empirical s- and p-wave amplitudes up to energies sâ1300 MeV in terms of the parameters relevant at order Q3.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
A. Gasparyan, M.F.M. Lutz,