Nucleon Polarizabilities from Low-Energy Compton Scattering
Abstract
An effective field theory is used to give a model-independent description of Compton scattering at energies comparable to the pion mass. The amplitudes for scattering on the proton and the deuteron, calculated to fourth order in small momenta in chiral perturbation theory, contain four undetermined parameters that are in one-to-one correspondence with the nucleon polarizabilities. These polarizabilities are extracted from fits to data on elastic photon scattering on hydrogen and deuterium. For the proton we find: alpha_p = 12.1 +/- 1.1 +/- 0.5, beta_p = 3.4 +/- 1.1 +/- 0.1, both in units of 10^{-4} fm^3. For the isoscalar polarizabilities we obtain: alpha_N = 13.0 +/- 1.9 +3.9/-1.5 (in the same units) while beta_N is consistent with zero, within sizeable error bars.
Cite
@article{arxiv.nucl-th/0209002,
title = {Nucleon Polarizabilities from Low-Energy Compton Scattering},
author = {S. R. Beane and M. Malheiro and J. A. McGovern and D. R. Phillips and U. van Kolck},
journal= {arXiv preprint arXiv:nucl-th/0209002},
year = {2008}
}
Comments
13 pages, 3 figures, uses revtex4, epsf. Replacement reflects version published in Physics Letters B. However, it also corrects incorrect results for the isoscalar polarizabilities that are present in both the previous archive and published versions. The results for the proton polarizabilities are unchanged