First Observation of Electroweak Single Top Quark Production

TL;DR

This paper reports the first observation of electroweak single top quark production in proton-antiproton collisions, confirming the Standard Model prediction with high statistical significance and measuring related parameters.

Contribution

It provides the first experimental evidence of single top quark production and measures its cross section and CKM matrix element |V_{tb}| with significant precision.

Findings

First observation of electroweak single top quark production

Measured cross section of 2.3 pb with uncertainties

Extracted CKM matrix element |V_{tb}|=0.91 +-0.11

Abstract

We report the first observation of single top quark production using 3.2 fb^-1 of pbar p collision data with sqrt{s}=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m_t=175 GeV/c^2, we measure a cross section of 2.3 +0.6 -0.5 (stat+syst) pb, extract the CKM matrix element value |V_{tb}|=0.91 +-0.11 (stat+syst) 0.07(theory), and set the limit |V_{tb}|>0.71 at the 95% C.L.