2,213 research outputs found

    Growing Things Rare, Foreign, and Tender : The Early Nineteenth-Century Greenhouse at Gore Place, Waltham Massachusetts

    Get PDF
    Excavations and ground penetrating radar at Gore Place in Waltham, Massachusetts, uncovered part of an early 19th-century greenhouse (ca. 1806 to the early 1840s) constructed by Christopher and Rebecca Gore. Documentary, archaeological, and geophysical data suggest that the greenhouse was a formal space intended to display exotic plants and that it was built in the relatively new lean-to style, with a tall back wall and a short front wall. The artifact assemblage included tools and small finds related to the greenhouse operation, as well as the remains of at least 149 planting pots. The greenhouse was constructed during a period of intense interest in agricultural experimentation by members of the Massachusetts commercial and political elite, including Gore. Scholars have argued that these men used the positive associations of agriculture to offset some of the contemporary negative connotations of commerce. This article examines the greenhouse in the light of this scientific agricultural movement but also argues that the greenhouse was an extension of the social space of the house and posits that Rebecca Gore may have played a significant role in managing it

    A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)

    Get PDF
    We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb1{\rm fb}^{-1} recorded at the Υ(4S)\Upsilon(4S) resonance and 3.9 fb1{\rm fb}^{-1} off-resonance. One of the neutral B mesons, which are produced in pairs at the Υ(4S)\Upsilon(4S), is fully reconstructed in the CP decay modes J/ψKS0J/\psi K^0_S, ψ(2S)KS0\psi(2S) K^0_S, χc1KS0\chi_{c1} K^0_S, J/ψK0J/\psi K^{*0} (K0KS0π0K^{*0}\to K^0_S\pi^0) and J/ψKL0J/\psi K^0_L, or in flavor-eigenstate modes involving D()π/ρ/a1D^{(*)}\pi/\rho/a_1 and J/ψK0J/\psi K^{*0} (K0K+πK^{*0}\to K^+\pi^-). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample finds Δmd=0.516±0.016(stat)±0.010(syst)ps1\Delta m_d = 0.516\pm 0.016 {\rm (stat)} \pm 0.010 {\rm (syst)} {\rm ps}^{-1}. The value of the asymmetry amplitude sin2β\sin2\beta is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B0B^0 decays in the CP-eigenstate modes. We find sin2β=0.59±0.14(stat)±0.05(syst)\sin2\beta=0.59\pm 0.14 {\rm (stat)} \pm 0.05 {\rm (syst)}, demonstrating that CP violation exists in the neutral B meson system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review

    A Search for Jet Handedness in Hadronic Z0Z^0 Decays

    Get PDF
    We have searched for signatures of polarization in hadronic jets from Z0qqˉZ^0 \to q \bar{q} decays using the ``jet handedness'' method. The polar angle asymmetry induced by the high SLC electron-beam polarization was used to separate quark jets from antiquark jets, expected to be left- and right-polarized, respectively. We find no evidence for jet handedness in our global sample or in a sample of light quark jets and we set upper limits at the 95% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing power of the method proposed by Efremov {\it et al.}Comment: Revtex, 8 pages, 2 figure

    Measurement of the Branching Fraction for B- --> D0 K*-

    Get PDF
    We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications

    Observation of time-reversal violation in the B0 meson system

    Get PDF
    The individually named authors work collectively as The BABAR Collaboration. Copyright @ 2012 American Physical Society.Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B0 or B¯¯¯0), and J/ψK0L or cc¯K0S final states (referred to as B+ or B−), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B¯¯¯0→B− and B−→B¯¯¯0, as a function of the time difference between the two B decays. Using 468×106 BB¯¯¯ pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS+T=−1.37±0.14(stat)±0.06(syst) and ΔS−T=1.17±0.18(stat)±0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.DOE and NSF (USA), NSERC (Canada), CEA and CNRS-IN2P3 (France), BMBF and DFG(Germany), INFN (Italy), FOM (The Netherlands), NFR (Norway), MES (Russia), MINECO (Spain), STFC (United Kingdom). Individuals have received support from the Marie Curie EIF (European Union), the A. P. Sloan Foundation (USA) and the Binational Science Foundation (USA-Israel)

    Measurement of Branching Fraction and Dalitz Distribution for B0->D(*)+/- K0 pi-/+ Decays

    Get PDF
    We present measurements of the branching fractions for the three-body decays B0 -> D(*)-/+ K0 pi^+/-andtheirresonantsubmodes and their resonant submodes B0 -> D(*)-/+ K*+/- using a sample of approximately 88 million BBbar pairs collected by the BABAR detector at the PEP-II asymmetric energy storage ring. We measure: B(B0->D-/+ K0 pi+/-)=(4.9 +/- 0.7(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K0 pi+/-)=(3.0 +/- 0.7(stat) +/- 0.3 (syst)) 10^{-4} B(B0->D-/+ K*+/-)=(4.6 +/- 0.6(stat) +/- 0.5 (syst)) 10^{-4} B(B0->D*-/+ K*+/-)=(3.2 +/- 0.6(stat) +/- 0.3 (syst)) 10^{-4} From these measurements we determine the fractions of resonant events to be : f(B0-> D-/+ K*+/-) = 0.63 +/- 0.08(stat) +/- 0.04(syst) f(B0-> D*-/+ K*+/-) = 0.72 +/- 0.14(stat) +/- 0.05(syst)Comment: 7 pages, 3 figures submitted to Phys. Rev. Let

    Branching fraction and form-factor shape measurements of exclusive charmless semileptonic B decays, and determination of |V_{ub}|

    Get PDF
    We report the results of a study of the exclusive charmless semileptonic decays, B^0 --> pi^- l^+ nu, B^+ --> pi^0 l^+ nu, B^+ --> omega l^+ nu, B^+ --> eta l^+ nu and B^+ --> eta^' l^+ nu, (l = e or mu) undertaken with approximately 462x10^6 B\bar{B} pairs collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses events in which the signal B decays are reconstructed with a loose neutrino reconstruction technique. We obtain partial branching fractions in several bins of q^2, the square of the momentum transferred to the lepton-neutrino pair, for B^0 --> pi^- l^+ nu, B^+ --> pi^0 l^+ nu, B^+ --> omega l^+ nu and B^+ --> eta l^+ nu. From these distributions, we extract the form-factor shapes f_+(q^2) and the total branching fractions BF(B^0 --> pi^- l^+ nu) = (1.45 +/- 0.04_{stat} +/- 0.06_{syst})x10^-4 (combined pi^- and pi^0 decay channels assuming isospin symmetry), BF(B^+ --> omega l^+ nu) = (1.19 +/- 0.16_{stat} +/- 0.09_{syst})x10^-4 and BF(B^+ --> eta l^+ nu) = (0.38 +/- 0.05_{stat} +/- 0.05_{syst})x10^-4. We also measure BF(B^+ --> eta^' l^+ nu) = (0.24 +/- 0.08_{stat} +/- 0.03_{syst})x10^-4. We obtain values for the magnitude of the CKM matrix element V_{ub} by direct comparison with three different QCD calculations in restricted q^2 ranges of B --> pi l^+ nu decays. From a simultaneous fit to the experimental data over the full q^2 range and the FNAL/MILC lattice QCD predictions, we obtain |V_{ub}| = (3.25 +/- 0.31)x10^-3, where the error is the combined experimental and theoretical uncertainty.Comment: 35 pages, 14 figures, submitted to PR

    Measurement of CP Asymmetries and Branching Fractions in Charmless Two-Body B-Meson Decays to Pions and Kaons

    Get PDF
    We present improved measurements of CP-violation parameters in the decays B0π+πB^0 \to \pi^+ \pi^-, B0K+πB^0 \to K^+ \pi^-, and B0π0π0B^0 \to \pi^0 \pi^0, and of the branching fractions for B0π0π0B^0 \to \pi^0 \pi^0 and B0K0π0B^0 \to K^0 \pi^0. The results are obtained with the full data set collected at the Υ(4S)\Upsilon(4S) resonance by the BABAR experiment at the PEP-II asymmetric-energy BB factory at the SLAC National Accelerator Laboratory, corresponding to 467±5467 \pm 5 million BBˉB\bar B pairs. We find the CP-violation parameter values and branching fractions Sπ+π=0.68±0.10±0.03,Cπ+π=0.25±0.08±0.02,AKπ+=0.107±0.0160.004+0.006,Cπ0π0=0.43±0.26±0.05,Br(B0π0π0)=(1.83±0.21±0.13)×106,Br(B0K0π0)=(10.1±0.6±0.4)×106, S_{\pi^+\pi^-} = -0.68 \pm 0.10 \pm 0.03, C_{\pi^+\pi^-} = -0.25 \pm 0.08 \pm 0.02, A_{K^-\pi^+} = -0.107 \pm 0.016 ^{+0.006}_{-0.004}, C_{\pi^0\pi^0} = -0.43 \pm 0.26 \pm 0.05, Br(B^0 \to \pi^0 \pi^0) = (1.83 \pm 0.21 \pm 0.13) \times 10^{-6}, Br(B^0 \to K^0 \pi^0) = (10.1 \pm 0.6 \pm 0.4) \times 10^{-6}, where in each case, the first uncertainties are statistical and the second are systematic. We observe CP violation with a significance of 6.7 standard deviations for B0π+πB^0 \to\pi^+\pi^- and 6.1 standard deviations for B0K+πB^0 \to K^+ \pi^-, including systematic uncertainties. Constraints on the Unitarity Triangle angle α\alpha are determined from the isospin relations among the BππB \to \pi\pi rates and asymmetries. Considering only the solution preferred by the Standard Model, we find α\alpha to be in the range [71,109][71^\circ,109^\circ] at the 68% confidence level.Comment: 18 pages, 11 postscript figures, submitted to Phys. Rev.
    corecore