Phys. Rev. Lett. 90, 141801 (2003) [5 pages]Measurements of the Decay KL→e+e-μ+μ-Received 2 December 2002; revised 18 February 2003; published 9 April 2003 The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay KL→e+e-μ+μ- , with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69±0.24(stat)±0.12(syst)]×10-9, with a radiative cutoff of Meeμμ 2/MK2>0.95. The first measurement using this mode of the parameter α from the D’Ambrosio-Isidori-Portolès (DIP) model of the KLγ*γ* vertex yields a result of -1.59±0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter β. We use this decay mode to set limits on CP and lepton violation. © 2003 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.90.141801
DOI:
10.1103/PhysRevLett.90.141801
PACS:
13.20.Eb, 11.30.Er, 12.15.Hh, 14.40.Aq
|
|
About | Terms and Conditions | Subscriptions | Search | Help
Use of the American Physical Society websites and journals implies that the user has read and agrees to our Terms and Conditions and any applicable Subscription Agreement. Physical Review®, Physical Review Letters®, Reviews of Modern Physics®, and Physical Review Special Topics® are trademarks of the American Physical Society.