We present a measurement of the ratio of the top-quark branching fractions R = B(t -> Wb)/B(t -> Wq), where q represents any quark flavor, in events with two charged leptons, imbalance in total transverse energy, and at least two jets. The measurement uses proton-antiproton collision data at center-of-mass energy 1.96 TeV, corresponding to an integrated luminosity of 8.7 fb(-1) collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure R to be 0.87 +/- 0.07, and extract the magnitude of the top-bottom quark coupling to be |V-tb| 0.93 +/- 0.04, assuming three generations of quarks. Under these assumptions, a lower limit of |V-tb| > 0.85(0.87) at 95% (90%) credibility level is set.
Measurement of B(t -> Wb)/B(t -> Wq) in Top-Quark-Pair Decays Using Dilepton Events and the Full CDF Run II Data Set
MARINO, PIETRO;MORELLO, MICHAEL JOSEPH;
2014
Abstract
We present a measurement of the ratio of the top-quark branching fractions R = B(t -> Wb)/B(t -> Wq), where q represents any quark flavor, in events with two charged leptons, imbalance in total transverse energy, and at least two jets. The measurement uses proton-antiproton collision data at center-of-mass energy 1.96 TeV, corresponding to an integrated luminosity of 8.7 fb(-1) collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure R to be 0.87 +/- 0.07, and extract the magnitude of the top-bottom quark coupling to be |V-tb| 0.93 +/- 0.04, assuming three generations of quarks. Under these assumptions, a lower limit of |V-tb| > 0.85(0.87) at 95% (90%) credibility level is set.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.