title: Observation of CP violation in K(L)-->pi(+)pi(-)e(+)e(-) decays
abstract: We report the first observation of a manifestly CP violating effect in the K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle straight phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This is the largest CP-violating effect yet observed when integrating over the entire phase space of a mode and the first such effect observed in an angular variable.
authors.affiliation: University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.initials: A
authors.lastname: Alavi-Harati
authors.initials: IF
authors.lastname: Albuquerque
authors.initials: T
authors.lastname: Alexopoulos
authors.initials: M
authors.lastname: Arenton
authors.initials: K
authors.lastname: Arisaka
authors.initials: S
authors.lastname: Averitte
authors.initials: AR
authors.lastname: Barker
authors.initials: L
authors.lastname: Bellantoni
authors.initials: A
authors.lastname: Bellavance
authors.initials: J
authors.lastname: Belz
authors.initials: R
authors.lastname: Ben-David
authors.initials: DR
authors.lastname: Bergman
authors.initials: E
authors.lastname: Blucher
authors.initials: GJ
authors.lastname: Bock
authors.initials: C
authors.lastname: Bown
authors.initials: S
authors.lastname: Bright
authors.initials: E
authors.lastname: Cheu
authors.initials: S
authors.lastname: Childress
authors.initials: R
authors.lastname: Coleman
authors.initials: MD
authors.lastname: Corcoran
authors.initials: G
authors.lastname: Corti
authors.initials: B
authors.lastname: Cox
authors.initials: MB
authors.lastname: Crisler
authors.initials: AR
authors.lastname: Erwin
authors.initials: R
authors.lastname: Ford
authors.initials: A
authors.lastname: Glazov