Dr Elizabeth Gallas

Abstract:

We present a search for electroweak production of single top quarks in ≈90 pb-1 of data collected with the DØ detector at the Fermilab Tevatron collider. Using arrays of neural networks to separate signals from backgrounds, we set upper limits on the cross sections of 17 pb for the s-channel process pp̄ → tb + X, and 22 pb for the t-channel process pp̄ → tqb + X, both at the 95% confidence level. © 2001 Elsevier Science B.V. All rights reserved.

Abstract:

The data collected by DO detector was used to study the decay of heavy particles into electron-positron pairs during collisions. The dielectron invariant mass spectra for the events with both electrons in central region and with one electron in central region and other in forward region of central calorimeter (CC)/end calorimeter (EC) were also studied. PYTHIA was used to determine the product of cross section and branching ratio for the system. The superimposed histograms represented the estimated spectrum from standard model processes and instrumental effects.

Abstract:

We present results of searches for technirho (rho(T)), techniomega (omega(T)), and Z' particles, using the decay channels rho(T),omega(T),Z'-->e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes pp-->rho(T),omega(T),Z'-->e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho(T) and omega(T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson.

Abstract:

We report a measurement of the differential cross section for W boson production as a function of its transverse momentum in proton-antiproton collisions at √s = 1.8 TeV. The data were collected by the DØ experiment at the Fermilab Tevatron Collider during 1994-1995 and correspond to an integrated luminosity of 85 pb-1. The results are in good agreement with quantum chromodynamics over the entire range of transverse momentum. © 2001 Elsevier Science B.V.

Abstract:

An overview is given of a search for new physics beyond the standard model, assuming nothing about the expected characteristics of the new processes other than they will produce an excess of events at high transverse momentum (PT). A quasi-model-independent strategy (Sleuth) is applied to many exclusive final states in a data sample corresponding to 100 pb1 of pp collisions. The resulting data is analyzed in detail.