Evidence for the decay K-L ->mu(+)mu(-)gamma gamma - art. no. 112001

Citation
A. Alavi-harati et al., Evidence for the decay K-L ->mu(+)mu(-)gamma gamma - art. no. 112001, PHYS REV D, 6211(11), 2000, pp. 2001
Citations number
12
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6211
Issue
11
Year of publication
2000
Database
ISI
SICI code
0556-2821(200012)6211:11<2001:EFTDK->2.0.ZU;2-1
Abstract
We have observed the decay K-L-->mu (+)mu (-)gamma gamma at the KTeV experi ment at Fermilab. This decay presents a formidable background to the search for new physics in K-L-->pi (0)mu (+)mu (-). The 1997 data yielded a sampl e of 4 signal events, with an expected background of 0.155+/-0.081 events. The branching ratio is beta (K-L -->mu (+)mu (-)gamma gamma)= [10.4(-5.9)(7.5) (stat)+/- 0.7 (syst)] x 10(-9) with m(gamma gamma)greater than or equa l to1 MeV/c(2), consistent with a QED calculation which predicts (9.1+/-0.8 ) x 10(-9).