A large-scale bulk flow of galaxy clusters
Astrophysical Journal 512:2 PART 2 (1999)
Abstract:
We report first results from the Streaming Motions of Abell Clusters (SMAC) project, an all-sky Fundamental Plane survey of 699 early-type galaxies in 56 clusters between ∼3000 and ∼14,000 km s-1. For this sample, with a median distance of ∼8000 km s-1, we find a bulk flow of amplitude 630 ± 200 km s-1 toward l = 260 ± 15°, b = -1 ± 12° with respect to the cosmic microwave background. The flow is robust against the effects of individual clusters and data subsets, the choice of Galactic extinction maps, Malmquist bias, and stellar population effects. The direction of the SMAC flow is ∼90° away from the flow found by Lauer & Postman, but it is in good agreement with the gravity dipole predicted from the distribution of X-ray-luminous clusters. Our detection of a high-amplitude coherent flow on such a large scale argues for excess mass density fluctuation power at wavelengths λ ≳ 60 h-1 Mpc, relative to the predictions of currently popular cosmological models.Measurement of the Bd 0-B̄d 0 flavor oscillation frequency and study of same side flavor tagging of B mesons in pp̄ collisions
Physical Review D - Particles, Fields, Gravitation and Cosmology 59:3 (1999) 1-41
Abstract:
Bd0-B̄d0 oscillations are observed in "self-tagged" samples of partially reconstructed B mesons decaying into a lepton and a charmed meson collected in pp̄ collisions at √s=1.8 TeV. A flavor tagging technique is employed which relies upon the correlation between the flavor of B mesons and the charge of a nearby particle. We measure the flavor oscillation frequency to be Δmd=0.471-0.068+0.078±0.034 ps-1. The tagging method is also demonstrated in exclusive samples of Bu+→J/ψK+ and Bd0→J/ψK*0(892), where similar flavor-charge correlations are observed. The tagging characteristics of the various samples are compared with each other, and with Monte Carlo simulations.Measurement of the BS 0 meson lifetime using semileptonic decays
Physical Review D - Particles, Fields, Gravitation and Cosmology 59:3 (1999) 1-14
Abstract:
The lifetime of the BS0 meson is measured using the semileptonic decay BS0→DS-l+νX. The data sample consists of about 110 pb-1 of pp̄ collisions at √s=1.8 TeV collected by the CDF detector at Fermilab. Four different DS- decay modes are reconstructed resulting in approximately 600 DS-l+ signal events. The BS0 meson lifetime is determined to be τ(BS0)=(1.36±0.09-0.05+0.06) ps, where the first and second uncertainties are statistical and systematic, respectively. The BS0 meson decay length distribution is examined for a lifetime difference ΔΓ/Γ between the two mass eigenstates of the BS0 meson. An upper limit of ΔΓ/Γ<0.83 is set at the 95% confidence level.Measurement of the mass splittings between the bb¯χb,J(1P) states
Physical Review D American Physical Society (APS) 59:3 (1999) 032003