Physics at BaBar

The BABAR detector at the SLAC PEP-II asymmetric e{sup +}e{sup -} collider has first started collecting data in May 1999. A study of time-dependent CP-violating asymmetries in B{sup 0} {yields} J/{psi} K{sub s}{sup 0} and B{sup 0} {yields} {psi}(2S) K{sub s}{sup 0} decays has been performed on a data sample of 9.0 fb{sup -1} taken at the {Upsilon}(4S) resonance and 0.8 fb{sup -1} off-resonance, collected through July 2000. The preliminary result sin2{beta} = 0.12 {+-} 0:37 (stat) {+-} 0.09 (syst) is presented here, together with preliminary results on neutral and charged B meson lifetimes and B{sup 0}{bar B}{sup 0} mixing.