Observation of CP violation in neutral B meson going to positive kaon-antipion and neutral B meson going to pion-antipion decays with the BABAR detector
This dissertation describes the measurement of asymmetries in neutral B meson decays to two-body final states of charged pions and kaons. The results are obtained from a data sample of 383 million ϒ(4 S) → BB¯ decays collected between 1999 and 2006 with the BABAR detector at the PEP-II asymmetric-energy B factory located at the Stanford Linear Accelerator Center, California.
The maximum likelihood fit that incorporates kinematical, event-shape, and particle identification information is used to measure the CP asymmetries in B0 → π +π− and K± π∓ decays. The direct CP-violating asymmetry between decays to K−π + is AKπ = −0.107 ± [special characters omitted]. The time-dependent CP-violating parameters in B0 → π+π− decays are Sππ = −0.60 ± 0.11 ± 0.03, Cππ = −0.21 ± 0.09 ± 0.02. For all the measurements above, the first error is statistical and the second is systematic.