Measurement of CP violation effects in $B_{d}^{0} \to J/\psi K_{s}^{0}$ in ATLAS

Direct measurements of the angles of the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle will be possible at the B-factories now being commissioned. The physics potential of the ATLAS experiment which will be a general purpose experiment at LHC to determine CP violation parameters from measurement of neutral B-meson decays is discussed. An estimation of the error in sin2 beta is presented for three years of running (corresponding to 30fb/sup -1/) based on reconstruction of the decay channel B/sub d//sup 0/ to J/ psi K/sub S //sup 0/ using two tagging methods. To determine the asymmetry that is due to CP violation, the asymmetry due to different production probabilities of B/sub d//sup 0/ and B/sub d//sup 0/ in pp collisions has to be subtracted from the measured asymmetry. The accuracy with which this production asymmetry can be measured has been estimated using the two control channels B/sub d//sup 0/ to J/ psi K/sup 0/* and B/sub d//sup 0/ to J/ psi K/sup +/. (7 refs).