Renormalization of the isovector $\pi N$ amplitude in pionic atoms
Abstract
The extraction of the isovector s-wave pi N amplitude from pionic atoms is studied with special emphasis on uncertainties and their dependence on the assumptions made regarding the neutron density distributions in nuclei and on the size of the data base used . Only `global' analyses of pionic-atom data reveal a discrepancy between the extracted isovector s-wave pi N amplitude b_1=-0.108\pm0.007 m_\pi^{-1} and its free pi N counterpart b_1^{free}=-0.0885^{+0.0010}_{-0.0021} m_\pi ^{-1}, where the uncertainty in the neutron densities is included in the error analysis. The role of `deeply bound' pionic atom states is discussed and the reason for failure of these states to provide new information is explained.
Keywords
Cite
@article{arxiv.nucl-th/0302038,
title = {Renormalization of the isovector $\pi N$ amplitude in pionic atoms},
author = {E. Friedman and A. Gal},
journal= {arXiv preprint arXiv:nucl-th/0302038},
year = {2009}
}
Comments
17 pages, 4 figures, slightly extended, accepted by NPA