95 research outputs found
Strategic Behaviour and Leadership Patterns of Modern Chief Justices
This study uses strategic behaviour, leadership change, and feminist theories to examine patterns of judicial activity by the three post-Charter chief justices of the Supreme Court of Canada. Building on prior scholarship, we use various methods to examine patterns of majority voting, dissenting activity, opinion writing, ideological voting, and panel size across the 1973 to 2014 period. While Chief Justices Lamer and Dickson exhibited clear patterns of task leadership, we find strong evidence of strategic change by Chief Justice McLachlin following her elevation to chief. She moved from a prolific dissenter as a puisne justice to a chief who exhibited behaviour of both a task leader and a social leader, which scholars see as highly uncommon. Her efforts to solidify her central role as a collegial leader within her own court, which took place during a period of increasing panel sizes and a shrinking court docket, are remarkable
Measurement of the W Boson Mass and Width Using a Novel Recoil Model
This dissertation presents a direct measurement of the W boson mass (M_W) and decay width (&Gamma_W) in 1 fb^(-1) of W &rarr e &nu collider data at D0 using a novel method to model the hadronic recoil. The mass is extracted from fits to the transverse mass M_T, p_T(e), and MET distributions. The width is extracted from fits to the tail of the M_T distribution. The electron energy measurement is simulated using a parameterized model, and the recoil is modeled using a new technique by which Z recoils are chosen from a data library to match the p_T and direction of each generated W boson. We measure the the W boson mass to be M_W = 80.4035 ± 0.024 (stat) ± 0.039 (syst) from the M_T, M_W = 80.4165 ± 0.027 (stat) ± 0.038 (syst) from the p_T(e), and M_W = 80.4025 ± 0.023 (stat) ± 0.043 (syst) from the MET distributions. &Gamma_W is measured to be &Gamma_W=2.025 ± 0.038 (stat) ± 0.061 (syst) GeV
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Design, Performance and Calibration of the CMS Forward Calorimeter Wedges
We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%
Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter
The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS
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