A. Samuel

Search for T and CP violation in B-0-(B)over-bar(0) mixing with inclusive dilepton events

We report the results of a search for T and CP violation in B0-anti-B0 mixing using an inclusive dilepton sample collected by the BaBar experiment at the PEP-II B Factory. The asymmetry between (l+,l+) and (l-,l-) events allows us to compare the probabilities P(anti-B0 ->B0) and P(B0 ->anti-B0) oscillations and thus probe T and CP invariance. Using a sample of 23 million B-anti-B pairs, we measure a same-sign dilepton asymmetry of A_(T/CP)=(0.5 +- 1.2(stat) +- 1.4(syst))%. For the modulus of the ratio of complex mixing parameters p and q, we obtain |q/p| = 0.998 +- 0.006(stat) +- 0.007(syst).

Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B-0 -> D*+D*

We present an updated measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D*+D*- using 232x10(6)BB pairs collected by the BABAR detector at the SLAC PEP-II B factory. We determine the CP-odd fraction to be 0.125+/-0.044(stat)+/-0.007(syst). The time-dependent CP asymmetry parameters C+ and S+ are determined to be 0.06+/-0.17(stat)+/-0.03(syst) and -0.75+/-0.25(stat)+/-0.03(syst), respectively. The standard model predicts these parameters to be 0 and -sin2beta, respectively, in the absence of penguin amplitude contributions.

Simultaneous measurement of the B0 meson lifetime and mixing frequency with B0→D*-ℓ+v ℓ decays

G. S. Abrams, A. W. Borgland, A. B. Breon, D. N. Brown, J. Button-Shafer, R. N. Cahn, E. Charles, M. S. Gill, A. V. Gritsan, Y. Groysman, R. G. Jacobsen, R. W. Kadel, J. Kadyk, L. T. Kerth, Yu. G. Kolomensky, J. F. Kral, C. LeClerc, M. E. Levi, G. Lynch, L. M. Mir, P. J. Oddone, T. J. Orimoto, M. Pripstein, N. A. Roe, A. Romosan, M. T. Ronan, V. G. Shelkov, A. V. Telnov, and W. A. Wenzel Lawrence Berkeley National Laboratory and University of California, Berkeley, CA 94720, USAWe measure the B^0 lifetime τ_B^0 and the B0−B0[overbar] oscillation frequency Δm_d with a sample of approximately 14000 exclusively reconstructed B^0→D*−l+ν_l signal events, selected from 23 million BB[overbar] pairs recorded at the Υ(4S) resonance with the BABAR detector at the Stanford Linear Accelerator Center. The decay position of the other B is determined with the remaining tracks in the event, and its b-quark flavor at the time of decay is determined with a tagging algorithm that exploits the correlation between the flavor of the b quark and the charges of its decay products. The lifetime and oscillation frequencies are measured simultaneously with an unbinned maximum-likelihood fit that uses, for each event, the measured difference in decay times of the two B mesons (Δt), the calculated uncertainty on Δt, the signal and background probabilities, and b-quark tagging information for the other B. The results are τ_B^0=(1.523^(+0.024)_(−0.023)±0.022)ps and Δm_d=(0.492±0.018±0.013)ps^(−1). The statistical correlation coefficient between τ_B0 and Δm_d is -0.22.

Study of the decay B¯0→D*+ωπ-

We report on a study of the decay B^0→D^(*+)ωπ^- with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232×10^6 BB decays, we measure the branching fraction B(B^0→D^(*+)ωπ^-)=(2.88±0.21(stat.)±0.31(syst.))×10^(-3). We study the invariant mass spectrum of the ωπ^- system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in τ-→ωπ-ν_τ. We also measure the polarization of the D^(*+) as a function of the ωπ^- mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D^(*+) to be ΓL/Γ=0.654±0.042(stat.)±0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as B^(-0)→D^(*+)ρ(1450)-, ρ(1450)^-→ωπ^-.We report on a study of the decay (B) over bar (0)-> D*+omega pi(-) with the BABAR detector at the PEP-II B-factory at the Stanford Linear Accelerator Center. Based on a sample of 232x10(6) B (B) over bar decays, we measure the branching fraction B((B) over bar (0)-> D*+omega pi(-))=(2.88 +/- 0.21(stat.)+/- 0.31(syst.))x10(-3). We study the invariant mass spectrum of the omega pi(-) system in this decay. This spectrum is in good agreement with expectations based on factorization and the measured spectrum in tau(-)->omega pi(-)nu(tau). We also measure the polarization of the D*+ as a function of the omega pi(-) mass. In the mass region 1.1 to 1.9 GeV we measure the fraction of longitudinal polarization of the D*+ to be Gamma(L)/Gamma=0.654 +/- 0.042(stat.)+/- 0.016(syst.). This is in agreement with the expectations from heavy-quark effective theory and factorization assuming that the decay proceeds as (B) over bar (0)-> D*+rho(1450)(-), rho(1450)(-)->omega pi(-).