Affiliation:
1. The Enrico Fermi Institute, The University of Chicago, 5640 South Ellis Avenue Chicago, IL 60637, USA
Abstract
We report on the analysis of the rare decay KL→μ+μ-γ using the 1997 data from the KTeV experiment at Fermilab. A total of 9327 candidate events are observed with 2.4% background, representing a factor of 40 increase in statistics over the current world sample. We find that BR(KL→μ+μ-γ)=(3.66±0.04stat±0.07syst)×10-7. The form factor parameter αK* is measured to the [Formula: see text]. We make the first measurement of the parameter α from the D'Ambrosio, Isidori, and Portolés form factor, finding α=-1.53±0.09. This measurement of α limits the CKM parameter ρ>-0.2.
Publisher
World Scientific Pub Co Pte Lt
Subject
Astronomy and Astrophysics,Nuclear and High Energy Physics,Atomic and Molecular Physics, and Optics