Kinematic Evidence for Top Quark Pair Production in WW + Multijet Events in ppˉp\bar{p} Collisions at s=1.8\sqrt{s} = 1.8 TeV

Collaboration
Dec, 1994
45 pages
Published in:
  • Phys.Rev.D 51 (1995) 4623-4637
e-Print:
Report number:
  • FERMILAB-PUB-94-411-E,
  • CDF-PUB-TOP-PUBLIC-2365,
  • ANL-HEP-PR-95-41
Experiments:

Citations per year

19952000200520102015051015
Abstract:
Study of W+W+multijet events that compares the kinematics of the observed events with expectations from direct QCD W+W+jet production and from production and decay of top quark pairs. The data were collected in the 1992-93 run with the Collider Detector at Fermilab from 19.3 pb 1~{-1} of proton-antiproton collisions at s=1.8\sqrt{s}=1.8 TeV. From the W+3W+\geq 3 jet events, a ``signal sample" with an improved ratio of ttˉt \bar{t} to QCD produced WW events is selected by requiring each jet to be emitted centrally in the event center of mass frame. This sample contains 14 events with unusually hard jet ET_T distributions not well described by expectations for jets from direct QCD WW production and other background processes. Using expected jet ET_T distributions, a relative likelihood is defined and used to determine if an event is more consistent with the decay of ttˉt \bar{t} pairs, with Mtop_{top}= 170 GeV/c 2~2, than with direct QCD WW production, while only 1.7 such top--like events are expected in the absence of ttˉt \bar{t}. Good agreement in the jet spectra is obtained if jet production from ttˉt \bar{t} pair decays is included. For those events kinematically more consistent with ttˉt \bar{t} we find evidence for a bb-quark content in their jets to the extent expected from top decay, and larger than expected for background processes. For events with four or more jets, the discrepancy with the predicted jet energy distributions from direct QCD WW production, and the associated excess of bb-quark content is more pronounced.
Note:
  • 45 pages (Latex), 17 uuencoded Postscript figures Report-no: FERMILAB-PUB-94/411-E
  • anti-p p: colliding beams
  • colliding beams: anti-p p
  • anti-p p: inclusive reaction
  • top
  • quark: pair production
  • pair production: quark
  • top: decay
  • decay: quark
  • final state: (W (n)jet)
  • (W (n)jet): final state