A systematic method of parameterisation estimation using data assimilation

In numerical weather prediction, parameterisations are used to simulate missing physics in the model. These can be due to a lack of scientific understanding or a lack of computing power available to address all the known physical processes. Parameterisations are sources of large uncertainty in a model as parameter values used in these parameterisations cannot be measured directly and hence are often not well known; and the parameterisations themselves are also approximations of the processes present in the true atmosphere. Whilst there are many efficient and effective methods for combined state/parameter estimation in data assimilation (DA), such as state augmentation, these are not effective at estimating the structure of parameterisations. A new method of parameterisation estimation is proposed that uses sequential DA methods to estimate errors in the numerical models at each space-time point for each model equation. These errors are then fitted to pre-determined functional forms of missing physics or parameterisations that are based upon prior information. We applied the method to a one-dimensional advection model with additive model error, and it is shown that the method can accurately estimate parameterisations, with consistent error estimates. Furthermore, it is shown how the method depends on the quality of the DA results. The results indicate that this new method is a powerful tool in systematic model improvement.

Search for squarks and gluinos in events with jets and missing transverse energy in p(p)over-bar collisions at root s-=1.96 TeV

The results of a search for squarks and gluinos using data from p (p) over bar collisions recorded at a center-of-mass energy of 1.96 TeV by the DO detector at the Fermilab Tevatron Collider are reported. The topologies analyzed consist of acoplanar-jet and multijet events with large missing transverse energy. No evidence for the production of squarks or gluinos was found in a data sample of 310pb(-1). Lower limits of 325 and 241 GeV were derived at the 95% C.L. on the squark and gluino masses, respectively, within the framework of minimal supergravity with tan beta=3, A(0) = 0, and mu < 0. (c) 2006 Elsevier B.V. All rights reserved.

Search for single top quarks in the tau plus jets channel using 4.8 fb(-1) of p(p)over-bar collision data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in p(p)over-bar collisions at root s=1.96 TeV

We present a search for the pair production of scalar top quarks, (t) over tilde, using 995 pb(-1) of data collected in p (p) over bar collisions with the Dempty set detector at the Fermilab Tevatron Collider at root s = 1.96 TeV. Both scalar top quarks are assumed to decay into a charm quark and a neutralino ((chi) over tilde (0)(1)), where (chi) over tilde (0)(1) is the lightest supersymmetric particle. This leads to a final state with two acoplanar charm jets and missing transverse energy. We find the yield of such events to be consistent with the standard model expectation, and exclude sets of (t) over tilde and (chi) over tilde (0)(1) masses at the 95% C.L. that substantially extend the domain excluded by previous searches. Published by Elsevier B.V.

Search for associated production of charginos and neutralinos in the trilepton final state using 2.3 fb(-1) of data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for supersymmetry in pp collisions at 7 TeV in events with jets and missing transverse energy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for scalar leptoquarks and T-odd quarks in the acoplanar jet topology using 2.5 fb(-1) of p(p)over-bar collision data at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for a heavy gauge boson W ' in the final state with an electron and large missing transverse energy in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for squark production in events with jets, hadronically decaying tau leptons and missing transverse energy at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for large extra dimensions via single photon plus missing energy final states at root s=1.96 TeV

We report on a search for large extra dimensions in a data sample of approximately 1 fb(-1) of p (p) over bar collisions at root s=1.96 TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale M(D) from 884 to 778 GeV for two to eight extra dimensions.

Search for Diphoton Events with Large Missing Transverse Energy in 6.3 fb(-1) of p(p)over-bar Collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for Supersymmetry in pp Collisions at root s=7 TeV in Events with Two Photons and Missing Transverse Energy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for first generation leptoquark pair production in the electron plus missing energy plus jets final state

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for New Physics with a Monojet and Missing Transverse Energy in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)