50,166 research outputs found
Accurate Estimation of the Trilinear Gauge Couplings Using Optimal Observables Including Detector Effects
This paper describes the definition of maximum likelihood equivalent
estimators of the Trilinear Gauge Couplings which include detector effects. The
asymptotic properties of these estimators as well as their unbiasedness and
efficiency when dealing with finite statistical samples are demonstrated by
Monte Carlo experimentation, using simulated events corresponding to the
production of q qbar lepton neutrino in e+ e- collisions at 172 GeV. Emphasis
is given to the determination of the expected efficiencies in extracting the
aWphi, aW and aBphi couplings from LEPII data, which in this particular case
found to be close to the maximum possible.Comment: 32 pages, 12 figures, Late
Likelihood inference for small variance components
In this paper, we develop likelihood-based methods for making inferences about the components of variance in a general normal mixed linear model. In particular, we use local asymptotic approximations to construct confidence intervals for the components of variance when the components are close to the boundary of the parameter space. In the process, we explore the question of how to profile the restricted likelihood (REML), show that general REML estimates have a lower probability of being on the boundary than maximum likelihood estimates, and show that the likelihood-ratio test based on the local asymptotic approximation has higher power against local alternatives than the likelihood-ratio test based on the usual chi-squared approximation. We explore the finite sample properties of the proposed intervals by means of a small simulation study
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