1,900 research outputs found
Great Fractured Moments in Courtroom History
Joseph Conrad described life as birth and death separated by struggle
The Exclusionary Rule and Police Perjury
This Article examines the legitimacy of the criticism of the Fourth Amendment exclusionary rule. In doing so, a general theme will emerge: the exclusionary rule is a benevolent concept crippled by police perjury and judicial hostility and seen as deserving a mercy killing by those who never wanted to give it life. It is the intent of this Article to explore the extent to which police perjury and judicial hostility have crippled the purpose and effect of the Fourth Amendment exclusionary rule. The conclusion will provide suggestions which, if implemented, could breathe new life into a beleaguered Fourth Amendment
The Data Acquisition and Calibration System for the ATLAS Semiconductor Tracker
The SemiConductor Tracker (SCT) data acquisition (DAQ) system will calibrate, configure, and control the approximately six million front-end channels of the ATLAS silicon strip detector. It will provide a synchronized bunch-crossing clock to the front-end modules, communicate first-level triggers to the front-end chips, and transfer information about hit strips to the ATLAS high-level trigger system. The system has been used extensively for calibration and quality assurance during SCT barrel and endcap assembly and for performance confirmation tests after transport of the barrels and endcaps to CERN. Operating in data-taking mode, the DAQ has recorded nearly twenty million synchronously-triggered events during commissioning tests including almost a million cosmic ray triggered events. In this paper we describe the components of the data acquisition system, discuss its operation in calibration and data-taking modes and present some detector performance results from these tests
Measurement of D⁰-D̅⁰ mixing using the ratio of lifetimes for the decays D⁰→K⁻π⁺ and K⁺K⁻
We measure the rate of D^0-D̅ ^0 mixing with the observable y_(CP)=(τ_(Kπ)/τ_(KK))-1, where τ_(KK) and τ_(Kπ) are, respectively, the mean lifetimes of CP-even D^0→K^+K^- and CP-mixed D^0→K^-π^+ decays, using a data sample of 384 fb^(-1) collected by the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory. From a sample of D^0 and D̅ ^0 decays where the initial flavor of the decaying meson is not determined, we obtain y_(CP)=[1.12±0.26(stat)±0.22(syst)]%, which excludes the no-mixing hypothesis at 3.3σ, including both statistical and systematic uncertainties. This result is in good agreement with a previous BABAR measurement of y_(CP) obtained from a sample of D^(*+)→D^0π^+ events, where the D^0 decays to K^-π^+, K^+K^-, and π^+π^-, which is disjoint with the untagged D^0 events used here. Combining the two results taking into account statistical and systematic uncertainties, where the systematic uncertainties are assumed to be 100% correlated, we find y_(CP)=[1.16±0.22(stat)±0.18(syst)]%, which excludes the no-mixing hypothesis at 4.1σ
Search for B-meson decays to b_1ρ and b_1K^*
We present a search for decays of B mesons to final states with a b_1 meson and a ρ or K^*(892) meson. The search is based on a data sample consisting of 465 million BB̅ pairs collected by the BABAR detector at the SLAC National Accelerator Laboratory. We do not observe any statistically significant signal. The upper limits we set on the branching fractions range from 1.4 to 8.0×10^(-6) at the 90% confidence level, including systematic uncertainties
Observation of the baryonic B-decay B̅⁰ → Λ꜀⁺ p̅K⁻π⁺
We report the observation of the baryonic B-decay B^0 → Λ^+_cpK^- π^+, excluding contributions from the decay B^0 → Λ^+_c ΛK^-. Using a data sample of 467 X 10^6 BB pairs collected with the BABAR detector at the PEP-II storage ring at SLAC, the measured branching fraction is (4:33 ± 0:82_(stat) ± 0:33_(syst) ± 1:13Λ^+_c) X 10^(-5). In addition we find evidence for the resonant decay B^0 → ∑_c (2455)^(++) pK^- and determine its branching fraction to be (1:11 ± 0:30_(stat) ± 0:09_(syst) ± 0:29_Λ^+_c) X 10^(-5). The errors are statistical, systematic, and due to the uncertainty in the Λ^+_c branching fraction. For the resonant decay B^0 → Λ^+_c pK^(*0) we obtain an upper limit of 2:42 X 10^(-5_ at 90% confidence level
Search for a Low-Mass Higgs Boson in Υ(3S)→γA^0, A^0→τ^+τ^- at BABAR
We search for a light Higgs boson A^0 in the radiative decay Υ(3S)→γA^0, A^0→τ^+τ^-, τ^+→e^+ν_eν̅ _τ, or τ^+→μ^+ν_μν̅_τ. The data sample contains 122×10^6 Υ(3S) events recorded with the BABAR detector. We find no evidence for a narrow structure in the studied τ^+τ^- invariant mass region of 4.03(1.5–16)×10^(-5) across the m_(τ+τ-) range. We also set a 90% C.L. upper limit on the τ^+τ^- decay of the η_b at B(η_b→τ^+τ^-)<8
Measurement of B→K^*(892)γ Branching Fractions and CP and Isospin Asymmetries
We present an analysis of the decays B^0→K^(*0)(892)γ and B^+→K^(*+)(892)γ using a sample of about 383×10^6 BB̅ events collected with the BABAR detector at the PEP-II asymmetric energy B factory. We measure the branching fractions B(B^0→K^(*0)γ)=(4.47±0.10±0.16)×10^(-5) and B(B^+→K^(*+)γ)=(4.22±0.14±0.16)×10^(-5). We constrain the direct CP asymmetry to be -0.033<A(B→K^*γ)<0.028 and the isospin asymmetry to be 0.017<Δ_(0-)<0.116, where the limits are determined by the 90% confidence interval and include both the statistical and systematic uncertainties
Search for gamma-ray emission from DES dwarf spheroidal galaxy candidates with Fermi-LAT data
Due to their proximity, high dark-matter (DM) content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection of DM. Recently, eight new dSph candidates were discovered using the first year of data from the Dark Energy Survey (DES). We searched for gamma-ray emission coincident with the positions of these new objects in six years of Fermi Large Area Telescope data. We found no significant excesses of gamma-ray emission. Under the assumption that the DES candidates are dSphs with DM halo properties similar to the known dSphs, we computed individual and combined limits on the velocity-averaged DM annihilation cross section for these new targets. If the estimated DM content of these dSph candidates is confirmed, they will constrain the annihilation cross section to lie below the thermal relic cross section for DM particles with masses ≲ 20 {GeV} annihilating via the b\bar{b} or tau+tau- channels
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