We have observed the decay KL→μ+μ-γγ at the KTeV experiment at Fermilab. This decay presents a formidable background to the search for new physics in KL→π0μ+μ-. The 1997 data yielded a sample of 4 signal events, with an expected background of 0.155±0.081 events. The branching ratio is script B sign (KL →μ+μ-γγ)=[10.4-5.9 +7.5(stat)±0.7(syst)]×10-9 with mγγ≥1 MeV/c2, consistent with a QED calculation which predicts (9.1±0.8)×10-9.
|Original language||English (US)|
|Number of pages||5|
|Journal||Physical Review D - Particles, Fields, Gravitation and Cosmology|
|State||Published - Dec 1 2000|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)