Truth and beauty together: Evidence for s-channel single top production
by
Yun-Tse Tsai(Rochester University)
→
US/Pacific
Madrone (Building 48 Room 224) (SLAC)
Madrone (Building 48 Room 224)
SLAC
Description
Single top quarks at the Tevatron are produced via the electroweak interaction from the decay of an off-shell W boson in the s-channel, or fusion of a virtual W boson with a b quark in the t-channel. In particular, the s-channel production rate is comparatively low at the LHC, and the much larger background contamination at the LHC would make it very difficult to measure the s-channel cross section.
In this talk, I will present the analysis that led to the first evidence for s-channel single top-quark production. The measurement is based on 9.7 fb-1 of ppbar collisions at sqrt{s} = 1.96 TeV collected with the D0 detector. Both the s and t-channel cross-sections are simultaneously measured without assuming the standard model prediction for either, and the CKM quark mixing element |Vtb|, which describes the Wtb coupling, is directly determined.