CP Violation in the B0 meson system with BaBar

The BABAR detector, at the PEP-II asymmetric B Factory at SLAC collected a sample of 32 million BBbar pairs whilst operating at energies near the Upsilon(4S) resonance between October 1999 and May 2001. An study of time-dependent CP-violating asymmetries in events where one neutral B meson is fully reconstructed in a final state containing charmonium produced the measurement sin2beta = 0.59 +- 0.14 (stat) +- 0.05 (syst), which constitutes an observation of CP violation in the B0 meson system at the 4 sigma level. Also presented are preliminary results from a study of CP violation in the decays B0 to pi+pi- and B0 to K+pi-.