Branching ratio measurement of the decay KL → e+e-μ+μ-

A. Alavi-Harati, T. Alexopoulos, M. Arenton, K. Arisaka, S. Averitte, R. F. Barbosa, A. R. Barker, M. Barrio, L. Bellantoni, A. Bellavance, J. Belz, R. Ben-David, D. R. Bergman, E. Blucher, G. J. Bock, C. Bown, S. Bright, E. Cheu, S. Childress, R. ColemanM. D. Corcoran, G. Corti, B. Cox, M. B. Crisler, A. R. Erwin, R. Ford, A. Glazov, A. Golossanov, G. Graham, J. Graham, K. Hagan, E. Halkiadakis, J. Hamm, K. Hanagaki, S. Hidaka, Y. B. Hsiung, V. Jejer, D. A. Jensen, R. Kessler, H. G.E. Kobrak, J. La Due, A. Lath, A. Ledovskoy, P. L. Mc Bride, P. Mikelsons, E. Monnier, T. Nakaya, K. S. Nelson, H. Nguyen, V. O. Dell, M. Pang, R. Pordes, V. Prasad, B. Quinn, X. R. Qi, E. J. Ramberg, R. E. Ray, A. Roodman, M. Sadamoto, S. Schnetzer, K. Senyo, P. Shanahan, P. S. Shawhan, J. Shields, W. Slater, N. Solomey, S. V. Somalwar, R. L. Stone, E. C. Swallow, S. A. Taegar, R. J. Tesarek, G. B. Thomson, P. A. Toale, A. Tripathi, R. Tschirhart, S. E. Turner, Y. W. Wah, J. Wang, H. B. White, J. Whitmore, B. Winstein, R. Winston, T. Yamanaka

Research output: Contribution to journalArticlepeer-review


We have collected a 43 event sample of the decay KL → e+e-μ+μ- with negligible backgrounds and measured its branching ratio to be (2.62 ± 0.40 ± 0.17) × 10-9. We see no evidence for CP violation in this decay. In addition, we set the 90% confidence upper limit on the combined branching ratios for the lepton flavor violating decays KL → e±e± μμ at B(KL → e±e±μ μ) ≤ 1.23 × 10-10, assuming a uniform phase space distribution.

Original languageEnglish (US)
Pages (from-to)111802
Number of pages1
JournalPhysical review letters
Issue number11
StatePublished - Jan 1 2001

ASJC Scopus subject areas

  • General Physics and Astronomy


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