Improved determination of the width of the top quark
2012 (English)In: Physical Review D, ISSN 1550-7998, Vol. 85, no 9, 091104- p.Article in journal (Refereed) Published
We present an improved determination of the total width of the top quark, Gamma(t), using 5.4 fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron p (p) over bar Collider. The total width Gamma(t) is extracted from the partial decay width Gamma(t -> Wb) and the branching fraction B(t -> Wb). Gamma(t -> Wb) is obtained from the t-channel single top-quark production cross section and B(t -> Wb) is measured in t (t) over bar events. For a top mass of 172.5 GeV, the resulting width is Gamma(t) = 2.00(-0.43)(+0.47) GeV. This translates to a top-quark lifetime of tau(t) = (3.29(-0.63)(+0.90)) x 10(-25) s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < vertical bar V-tb vertical bar <= 1 at 95% C.L. and a limit of vertical bar V-tb'vertical bar < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.
Place, publisher, year, edition, pages
2012. Vol. 85, no 9, 091104- p.
IdentifiersURN: urn:nbn:se:su:diva-80099DOI: 10.1103/PhysRevD.85.091104ISI: 000303659200003OAI: oai:DiVA.org:su-80099DiVA: diva2:555256