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

Abstract

We present a study of $W+$multijet events that compares the kinematics of the observed events with expectations from direct QCD $W+$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${}^{-1}$ of proton-anti proton collisions at $\sqrt{s}=1.8$ TeV. From the $W+\ge 3$ jet events, a "signal sample" with an improved ratio of $t\bar{t}$ to QCD produced $W$ 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 E${}_T$ distributions not well described by expectations for jets from direct QCD $W$ production and other background processes. Using expected jet E${}_T$ distributions, a relative likelihood is defined and used to determine if an event is more consistent with the decay of $t\bar{t}$ pairs, with M${}_{top}$~=~ 170 GeV/c${}^2$, than with direct QCD $W$ production, while only 1.7 such top--like events are expected in the absence of $t\bar{t}$. Good agreement in the jet spectra is obtained if jet production from $t\bar{t}$ pair decays is included. For those events kinematically more consistent with $t\bar{t}$ we find evidence for a $b$-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 $W$ production, and the associated excess of $b$-quark content is more pronounced.

45 pages (Latex), 17 uuencoded Postscript figures, correction of abstract

References in corpus (3)

• Evidence for Top Quark Production in $\bar{p}p$ Collisions at $\sqrt{s}=1.8$ TeV
• Top Quark Production Cross Section
• Search for High Mass Top Quark Production in p anti-p Collisions at S**(1/2) = 1.8 TeV

Cited by in corpus (25)

• Weak Decays Beyond Leading Logarithms
• Precision SUSY Measurements at LHC
• Direct Measurement of the Top Quark Mass at D0
• Quark Singlets: Implications and Constraints
• Constraining Anomalous Top Quark Couplings at the Tevatron
• Measurement of the Top Quark Mass with the Collider Detector at Fermilab
• Rare B \to K^{(*)} ν\barνDecays at B Factories
• Top quark physics in hadron collisions
• Measurement of the Cross Section for $t\bar{t}$ Production in $p\bar{p}$ Collisions using the Kinematics of Lepton+Jets Events
• Renormalization group evolution of R-parity-violating Yukawa couplings
• Single Top Quark Production as a Probe for Anomalous Moments at Hadron Colliders
• The discovery of the top quark
• Theoretical Review of B-Physics
• Measurement of the p anti-p to t anti-t Production Cross Section and the Top Quark Mass at sqrt{s}=1.96 TeV in the All-Hadronic Decay Mode
• Search for a Fourth-Generation Quark More Massive than the Z0 Boson in ppbar Collisions at sqrt(s) = 1.8 TeV
• Test of Analysis Method for Top-Antitop Production and Decay Events
• Rare top quark decay t --> u_1 \bar{u}_2 u_2 in the standard model
• Review of Properties of the Top Quark from Measurements at the Tevatron
• Study of ttbar Production in ppbar Collisions Using Total Transverse Energy
• Properties of Jets in W Boson Events from 1.8 TeV pbar p Collisions
• Observation of Hadronic W Decays in t-tbar Events with the Collider Detector at Fermilab
• Search for the Supersymmetric Partner of the Top-Quark in $p\bar{p}$ Collisions at $\sqrt{s}=1.8\mathrm{TeV}$
• Higgs mediated Double Flavor Violating top decays in Effective Theories
• Can We Observe Weak Anomalous Couplings of Heavy Quarks Through Three Jet Events?
• Top pair production with an extra gluon at the Tevatron