Scientific article
English

Kinematic evidence for top quark pair production in W+multijet events in pp¯ collisions at √s =1.8 TeV

ContributorsCDF Collab.
CollaboratorsProduit, Nicolasorcid
Published inPhysical review. D. Particles and fields, vol. 51, no. 9, p. 4623-4637
Publication date1995
First online date1995-05-01
Abstract

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-antiproton collisions at $\sqrt{s}=1.8$ TeV. From the $W+\geq 3$ 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.

Keywords
  • 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
  • W: hadroproduction
  • Hadroproduction: W
  • Jet: multiplicity
  • Kinematics
  • Particle identification: bottom
  • Channel cross section
  • Energy spectrum: transverse energy
  • Transverse energy: energy spectrum
  • Angular distribution
  • Mass: top
  • Top: mass
  • Numerical calculations: Monte Carlo
  • CDF
  • Experimental results
  • Batavia TEVATRON Coll
  • 1800 GeV-cms
Affiliation entities Not a UNIGE publication
Citation (ISO format)
CDF Collab. Kinematic evidence for top quark pair production in W+multijet events in pp¯ collisions at √s =1.8 TeV. In: Physical review. D. Particles and fields, 1995, vol. 51, n° 9, p. 4623–4637. doi: 10.1103/physrevd.51.4623
Main files (2)
Article (Published version)
accessLevelRestricted
Article (Submitted version)
accessLevelPublic
Identifiers
Additional URL for this publicationhttps://link.aps.org/doi/10.1103/PhysRevD.51.4623
Journal ISSN0556-2821
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