Observation of Top Quark Production in Pbar-P Collisions

TL;DR

This paper reports the first observation of the top quark in proton-antiproton collisions, confirming its existence with significant statistical evidence, and measures its mass and production cross section.

Contribution

First experimental observation of the top quark using collider data, establishing its mass and production rate with statistical significance.

Findings

Top quark observed with 4.8 sigma significance.

Measured top quark mass is 176 +/- 8 (stat) +/- 10 (sys.) GeV/c^2.

Top-antitop production cross section is 6.8 +3.6 -2.4 pb.

Abstract

We establish the existence of the top quark using a 67 pb^-1 data sample of Pbar-P collisions at Sqrt(s) = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). Employing techniques similar to those we previously published, we observe a signal consistent with t-tbar decay to WW b-bbar, but inconsistent with the background prediction by 4.8 sigma. Additional evidence for the top quark is provided by a peak in the reconstructed mass distribution. We measure the top quark mass to be 176 +/-8(stat) +/- 10(sys.) GeV/c^2, and the t-tbar production cross section to be 6.8 +3.6 -2.4 pb.