Experimental status of the electric and magnetic polarizabilities of a proton

Citation
Ps. Baranov et al., Experimental status of the electric and magnetic polarizabilities of a proton, PHYS PART N, 32(3), 2001, pp. 376-394
Citations number
111
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Physics
Journal title
PHYSICS OF PARTICLES AND NUCLEI
ISSN journal
1063-7796 → ACNP
Volume
32
Issue
3
Year of publication
2001
Pages
376 - 394
Database
ISI
SICI code
1063-7796(200105/06)32:3<376:ESOTEA>2.0.ZU;2-W
Abstract
For the first time, a global analysis of all (early and recent) experimenta l data on the differential cross section of elastic gammap scattering at ph oton energies omega < 150 MeV is carried out with the AIM of determining th e electric (<alpha>(p)) and magnetic (beta (p)) polarizabilities of a proto n. The fit of the data by the theoretical cross section with two free param eters alpha (p) and beta (p) obtained on the basis of s-channel dispersion relations at a finite energy gives the world average experimental values of proton polarizabilities: alpha (exp)(p) = 11.7 +/- 0.8 +/- 0.7 and beta (e xp)(p) = 2.3 +/- 0.9 +/- 0.7 (in units of 10(-4) fm(3)), where the first (c ombined) error represents the statistical and systematical errors of experi mental cross sections; the second error, theoretical uncertainties of the d ispersion cross section. It is emphasized that more complete and precise da ta at omega less than or similar to 100 MeV will enable one to reduce the t heoretical and experimental errors in the values of alpha (p) and beta (p).