Skip to Main content Skip to Navigation
Journal articles

Measurement of the ratio B(t to Wb)/B(t to Wq) in pp collisions at sqrt(s) = 8 TeV

Abstract : The ratio of the top-quark branching fractions R=B(t to Wb)/B(t to Wq), where the denominator includes the sum over all down-type quarks (q = b, s, d), is measured in the t t-bar dilepton final state with proton-proton collision data at sqrt(s)=8 TeV from an integrated luminosity of 19.7 inverse femtobarns, collected with the CMS detector. In order to quantify the purity of the signal sample, the cross section is measured by fitting the observed jet multiplicity, thereby constraining the signal and background contributions. By counting the number of b jets per event, an unconstrained value of R=1.014 +/- 0.003 (stat.) +/- 0.032 (syst.) is measured, in good agreement with the standard model prediction. A lower limit R>0.955 at the 95% confidence level is obtained after requiring R<=1, and a lower limit on the Cabibbo-Kobayashi-Maskawa matrix element abs(V[tb])>0.975 is set at 95% confidence level. The result is combined with a previous CMS measurement of the t-channel single-top-quark cross section to determine the top-quark total decay width, Gamma[t]=1.36 +/- 0.02 (stat.) +0.14/-0.11 (syst.) GeV.
Document type :
Journal articles
Complete list of metadata
Contributor : Sylvie Flores Connect in order to contact the contributor
Submitted on : Thursday, April 10, 2014 - 7:20:25 AM
Last modification on : Monday, March 28, 2022 - 9:39:18 AM

Links full text



V. Khachatryan, S. Baffioni, F. Beaudette, P. Busson, C. Charlot, et al.. Measurement of the ratio B(t to Wb)/B(t to Wq) in pp collisions at sqrt(s) = 8 TeV. Physics Letters B, Elsevier, 2014, 736, pp.33-57. ⟨10.1016/j.physletb.2014.06.076⟩. ⟨in2p3-00976528⟩



Record views