Observation of the top quark

Technical Report · Mon May 01 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/79708· OSTI ID:79708

Thompson, J ^[1]

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1. Maryland Univ., College Park, MD (United States)

The D0 collaboration reports on a search for the Standard Model top quark in p{bar p} collisions at {radical}s = 1.8 TeV at the Femlilab Tevatron, with an integrated luminosity of approximately 50 pb{sup {minus}1}. We have searched for t{bar t} production in the dilepton and single-lepton decay channels, with and without tagging of b quark jets. We observe 17 events with an expected background of 3.8 {plus_minus} 0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2 {delta} 10{sup {minus}6} (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199{sub {minus}21}{sup +19} (stat.) {plus_minus}22 (syst.) GeV/c{sup 2} and its production cross section to be 6.4 {plus_minus} 2.2 pb.

• Research Organization: Fermi National Accelerator Lab., Batavia, IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-76CH03000
• OSTI ID: 79708
• Report Number(s): FNAL/C--95/106-E; CONF-9503158--5; ON: DE95013584
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CROSS SECTIONS
EXPERIMENTAL DATA
FERMILAB TEVATRON
PARTICLE IDENTIFICATION
PARTICLE PRODUCTION
PROTON-ANTIPROTON INTERACTIONS
QUARKS
REST MASS
STANDARD MODEL
TOP PARTICLES