A quark model calculation of gamma gamma ->pi pi including final-state interactions - art. no. 025203

Authors
Blundell, HG Godfrey, S Hay, G Swanson, ES
Citation
Hg. Blundell et al., A quark model calculation of gamma gamma ->pi pi including final-state interactions - art. no. 025203, PHYS REV C, 6102(2), 2000, pp. 5203
Citations number
36
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW C-NUCLEAR PHYSICS
ISSN journal
05562813 → ACNP
Volume
6102
Issue
2
Year of publication
2000
Database
ISI
SICI code
0556-2813(200002)6102:2<5203:AQMCOG>2.0.ZU;2-U
Abstract
A quark model calculation of the processes gamma gamma --> pi(+) pi(-) and gamma gamma --> pi(0) pi(0) is performed. At tree level, only charged pions couple to the initial state photons and neutral pions are not expected in the final state. However, a small but significant gamma gamma --> pi(0) pi( 0) cross section is observed. We demonstrate that this may be accounted for by a rotation in isospin space induced by final-state interactions. The re sulting pi(+) pi(-) cross section is In good agreement with experiment; whi le the pi(0) pi(0) cross section is in qualitative agreement with the data.