Measurement of the branching ratio and asymmetry of the decay Xi degrees -> Sigma degrees gamma

Citation
A. Alavi-harati et al., Measurement of the branching ratio and asymmetry of the decay Xi degrees -> Sigma degrees gamma, PHYS REV L, 86(15), 2001, pp. 3239-3243
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
0031-9007 → ACNP
Volume
86
Issue
15
Year of publication
2001
Pages
3239 - 3243
Database
ISI
SICI code
0031-9007(20010409)86:15<3239:MOTBRA>2.0.ZU;2-O
Abstract
We have studied the rare weak radiative hyperon decay Xi degrees --> Sigma degrees gamma in the KTeV experiment at Fermilab. We have identified 4045 s ignal events over a background of 804 events. The dominant Xi degrees --> L ambda pi degrees decay, which was used for normalization, is the only impor tant background source. An analysis of the acceptance of both modes yields a branching ratio of B(Xi degrees --> Sigma degrees gamma) / B(Xi degrees - -> Lambda pi degrees) = (3.34 +/- 0.05 +/- 0.09) X 10(-3). By analyzing the final state decay distributions, we have also determined that the Sigma de grees emission asymmetry parameter for this decay is alpha (Xi Sigma) = -0. 63 +/- 0.09.