CHIRAL RESTORATION AND THE EXTENDED PHOTOABSORPTION SUM-RULE IN NUCLEI

Authors
ERICSON M ROSACLOT M KULAGIN SA
Citation
M. Ericson et al., CHIRAL RESTORATION AND THE EXTENDED PHOTOABSORPTION SUM-RULE IN NUCLEI, Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields, 111(1), 1998, pp. 75-83
Citations number
13
Categorie Soggetti
Physics, Particles & Fields
Journal title
Nuovo cimento della Società Italiana di Fisica. A. Nuclei, particles and fields → ACNP
ISSN journal
11241861
Volume
111
Issue
1
Year of publication
1998
Pages
75 - 83
Database
ISI
SICI code
1124-1861(1998)111:1<75:CRATEP>2.0.ZU;2-I
Abstract
The Bethe-Levinger sum rule is extended beyond the potential model. Th e pion degrees of freedom are taken into account and the modifications of the potential theory are analysed within a dispersion relation on the Compton amplitude. Our aim is to extract from the photon data expe rimental information on the expectation value of the square of the pio n field, a quantity which enters also in the restoration of chiral sym metry in nuclei. We are led to incorporate in the description the Delt a resonance, which is strongly excited by the pion degrees of freedom.