Rights statement: © 2012 American Physical Society
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - An improved determination of the width of the top quark
AU - Collaboration, D0
AU - Bertram, Iain
AU - Borissov, Guennadi
AU - Fox, Harald
AU - Ross, Anthony
AU - Williams, Mark
AU - Ratoff, Peter
N1 - © 2012 American Physical Society 8 pages, 4 figures, submitted to Phys. Rev. D (RC)
PY - 2012/5/4
Y1 - 2012/5/4
N2 - 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 $p\bar{p}$ Collider. The total width $\Gamma_t$ is extracted from the partial decay width $\Gamma(t\to Wb)$ and the branching fraction $\mathcal{B}(t\to Wb)$. $\Gamma(t\to Wb)$ is obtained from the $t$-channel single top quark production cross section and $\mathcal{B}(t\to Wb)$ is measured in $t\bar{t}$ events. For a top mass of $172.5\;\rm GeV$, the resulting width is $\Gamma_t = 2.00^{+0.47}_{-0.43}$ GeV. This translates to a top-quark lifetime of $\tau_t = (3.29^{+0.90}_{-0.63})\times10^{-25}$ s. We also extract an improved direct limit on the CKM matrix element $0.81 $|V_{tb}| 0.59$ for a high mass fourth generation bottom quark assuming unitarity of the fourth generation quark mixing matrix.
AB - 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 $p\bar{p}$ Collider. The total width $\Gamma_t$ is extracted from the partial decay width $\Gamma(t\to Wb)$ and the branching fraction $\mathcal{B}(t\to Wb)$. $\Gamma(t\to Wb)$ is obtained from the $t$-channel single top quark production cross section and $\mathcal{B}(t\to Wb)$ is measured in $t\bar{t}$ events. For a top mass of $172.5\;\rm GeV$, the resulting width is $\Gamma_t = 2.00^{+0.47}_{-0.43}$ GeV. This translates to a top-quark lifetime of $\tau_t = (3.29^{+0.90}_{-0.63})\times10^{-25}$ s. We also extract an improved direct limit on the CKM matrix element $0.81 $|V_{tb}| 0.59$ for a high mass fourth generation bottom quark assuming unitarity of the fourth generation quark mixing matrix.
U2 - 10.1103/PhysRevD.85.091104
DO - 10.1103/PhysRevD.85.091104
M3 - Journal article
VL - 85
JO - Physical Review D
JF - Physical Review D
SN - 1550-7998
IS - 9
M1 - 091104(R)
ER -