Measurement of the branching ratio and form factor of K-L -> mu(+) mu(-) gamma - art. no. 071801

Citation
A. Alavi-harati et al., Measurement of the branching ratio and form factor of K-L -> mu(+) mu(-) gamma - art. no. 071801, PHYS REV L, 8707(7), 2001, pp. 1801
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
0031-9007 → ACNP
Volume
8707
Issue
7
Year of publication
2001
Database
ISI
SICI code
0031-9007(20010813)8707:7<1801:MOTBRA>2.0.ZU;2-2
Abstract
We report on the analysis of the rare decay K-L--> mu (+)mu (-)gamma the 19 97 data from the KTeV experiment at Fermilab. A total of 9327 candidate eve nts are observed with 2.4% background, representing a factor of 40 increase in statistics over the current world sample. We find that B(K-L --> mu (+) mu (-)gamma) = (3.62 +/-0.04(stat)+/-0.08(syst)) x 10(-7). The form factor parameter alpha (K*) is measured to be alpha (K*) = -0.160(-0.028)(+0.026). In addition, we make the first measurement of the parameter alpha from the D'Ambrosio-Isidori-Portoles form factor, finding alpha = -1.54 +/-0.10. In that model, this alpha measurement limits the Cabibbo-Kobayashi-Maskawa pa rameter rho > -0.2.