Measurement of ε′ε in the neutral kaon system

R. H. Bernstein, G. J. Bock, D. Carlsmith, D. Coupal, J. W. Cronin, G. D. Gollin, Wen Keling, K. Nishikawa, H. W.M. Norton, B. Winstein, B. Peyaud, R. Turlay, A. Zylberstejn

Research output: Contribution to journalArticlepeer-review


A measurement of the ratio of the CP-nonconservation parameters, ε′ε, in the K0K̄0 system was performed through a study of two-pion decays with and without a regenerator. To reduce systematic effects, KL and KS decays were recorded simultaneously with a double beam. Over 3100 KL→2π0 events were reconstructed leading to the result ε′ε=-0.0046±0.0053±0.0024 (the first error is statistical, the second systematic). The measurement agrees with previous less precise determinations but, because of theoretical uncertainties, is not able to test decisively the Kobayashi-Maskawa mechanism.

Original languageEnglish (US)
Pages (from-to)1631-1634
Number of pages4
JournalPhysical review letters
Issue number15
StatePublished - 1985
Externally publishedYes

ASJC Scopus subject areas

  • General Physics and Astronomy


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