Studies of WW and WZ production and limits on anomalous WWγ and WWZ couplings -: art. no. 072002
PHYSICAL REVIEW D 60:7 (1999) ARTN 072002
Probing hard color-singlet exchange in pp̄ collisions at √s = 630 GeV and 1800 GeV
Physics Letters Section B Nuclear Elementary Particle and High Energy Physics 440:1-2 (1998) 189-202
Abstract:
We present results on dijet production via hard color-singlet exchange in proton-antiproton collisions at √s = 630 GeV and 1800 GeV using the DØ detector. The fraction of dijet events produced via color-singlet exchange is measured as a function of jet transverse energy, separation in pseudorapidity between the two highest transverse energy jets, and proton-antiproton center-of-mass energy. The results are consistent with a color-singlet fraction that increases with an increasing fraction of quark-initiated processes and inconsistent with two-gluon models for the hard color-singlet. © 1998 Published by Elsevier Science B.V. All rights reserved.Direct measurement of the top quark mass by the DØ Collaboration
Physical Review D - Particles, Fields, Gravitation and Cosmology 58:5 (1998)
Abstract:
We determine the top quark mass mt using tt̄ pairs produced in the DØ deteetor by √s = 1.8 TeV pp̄ collisions in a 125 ph-1 exposure at the Fermilab Tevatron. We make a two constraint fit to mt in tt̄→bW+b̄W- final states with one W boson decaying to qq̄ and the other to eν or μν. Likelihood fits to the data yield mt(l+jets) = 173.3±5.6 (stat) ± 5.5 (syst) GeV/c2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain mt = 172.1 ± 5.2 (stat) ± 4.9 (syst) GeV/c2. An alternate analysis, using three constraint fits to fixed top quark masses, gives mt(l + jets) = 176.0 ± 7.9 (stat) ± 4.8 (syst) GeV/c2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented.Limits on WWγ and WWZ couplings from W boson pair production
Physical Review D Particles Fields Gravitation and Cosmology 58:5 (1998) 511011-511016
Abstract:
The results of a search for W boson pair production in pp̄ collisions at √s = 1.8 TeV with subsequent decay to eμ, ee, and μμ channels are presented. Five candidate events are observed with an expected background of 3.1 ± 0.4 events for an integrated luminosity of approximately 97 pb-1. Limits on the anomalous couplings are obtained from a maximum likelihood fit of the ESearch for trilepton signatures from associated gaugino pair production
Physical Review Letters 80:8 (1998) 1591-1596