Observation of Single Top Quark Production with the D0 Detector

TL;DR

This paper reports the first observation of single top quark production at the Fermilab Tevatron, using advanced multivariate analysis techniques to achieve a 5 sigma significance and measure the production cross section.

Contribution

It presents the first observation of single top quark production with a significance of 5 sigma and measures the cross section and CKM matrix element Vtb using the D0 detector.

Findings

Measured single top cross section: 3.94+-0.88 pb

Significance of observation: 5.0 standard deviations

Lower limit on |Vtb|: >0.78

Abstract

We report on the observation of single top quark production by the D0 collaboration using a dataset of 2.3 fb^-1 collected at the Fermilab Tevatron ppbar collider. Several multivariate techniques are combined to separate the single top signal from backgrounds. The measured single top cross section is 3.94+-0.88pb. The probability to measure a cross section at this value or higher in the absence of signal is 2.9*10^-7, corresponding to a 5.0 standard deviation significance for the presence of signal. The lower limit at the 95% C.L. on the CKM matrix element Vtb is |Vtb|>0.78. A separate measurement of the t-channel cross section gives 3.14 +0.94 -0.80 pb.