Observation of CP Violation in the B{sup 0} Meson System
D. B. MacFarlane
Abstract
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D. B. MacFarlane
Abstract
Open-access reader
We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of {Upsilon}(4S) decays collected in 2001, bringing the data available to 32 million B{bar B} pairs. We select events in which one neutral B meson is fully reconstructed in final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2{beta}, is derived from the decay time distributions in such events. The result sin2{beta} = 0.59 {+-} 0.14 (stat) {+-} 0.05 (syst) establishes CP violation in the B{sup 0} meson system. We also determine |{lambda}| = 0.93 {+-} 0.09 (stat) {+-} 0.03 (syst), consistent with no direct CP violation.
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We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of {Upsilon}(4S) decays collected in 2001, bringing the data available to 32 million B{bar B} pairs. We select events in which one neutral B meson is fully reconstructed in final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2{beta}, is derived from the decay time distributions in such events. The result sin2{beta} = 0.59 {+-} 0.14 (stat) {+-} 0.05 (syst) establishes CP violation in the B{sup 0} meson system. We also determine |{lambda}| = 0.93 {+-} 0.09 (stat) {+-} 0.03 (syst), consistent with no direct CP violation.
Key concepts: Physics, Particle physics, B meson, CP violation, Meson, B-factory, Asymmetry, Nuclear physics