Low-energy Compton scattering and the polarizabilities of the proton

Citation
Vo. De Leon et al., Low-energy Compton scattering and the polarizabilities of the proton, EUR PHY J A, 10(2), 2001, pp. 207-215
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
EUROPEAN PHYSICAL JOURNAL A
ISSN journal
1434-6001 → ACNP
Volume
10
Issue
2
Year of publication
2001
Pages
207 - 215
Database
ISI
SICI code
1434-6001(200102)10:2<207:LCSATP>2.0.ZU;2-X
Abstract
Differential cross-sections for Compton scattering from the proton hal e be en measured at the MAMI tagged photon facility using the TAPS setup. The da ta cover an angular range of theta (lab)(gamma) = 59 degrees -155 degrees a nd photon energies ranging from 55 MeV to 165 MeV. Our results are in good agreement with those from previous experiments, but yield higher precision. Using dispersion relations the proton polarizabilities have been determine d to be <(<alpha>)over bar> = [11.9 +/- 0.5(stat.) -/+ 1.3(syst.) +/- 0.3(m od.)] (.) 10(-4) fm(3) and <(<beta>)over bar> = [1.2 +/- 0.7(stat.) +/- 0.3 (syst). +/- 0.4(mod.))] (.) 10(-4) fm(3). These results confirm the Baldin sum rule which was re-evaluated to be <(<alpha>)over bar> + <(<beta>)over b ar> = [13.8 +/- 0.4] 10(-4) fm(3). We can also conclude that there is no si gnificant additional asymptotic contribution to the backward spin polarizab ility gamma (pi) beyond the t-channel pi (0)-exchange.