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arXiv · 0704.0594

Search for a fourth generation b'-quark at LEP-II at sqrt{s}=196-209 GeV

The DELPHI Collaboration·J. Abdallah
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Abstract

A search for the pair production of fourth generation b'-quarks was performed using data taken by the DELPHI detector at LEP-II. The analysed data were collected at centre-of-mass energies ranging from 196 to 209 GeV, corresponding to an integrated luminosity of 420 pb^{-1}. No evidence for a signal was found. Upper limits on BR(b' -> bZ) and BR(b' -> cW) were obtained for b' masses ranging from 96 to 103 GeV/c^2. These limits, together with the theoretical branching ratios predicted by a sequential four generations model, were used to constrain the value of R_{CKM}=|V_{cb'}/V_{tb'}V_{tb}|, where V_{cb'}, V_{tb'} and V_{tb} are elements of the extended CKM matrix.

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The DELPHI Collaboration, J. Abdallah. 2007-04-04. Search for a fourth generation b'-quark at LEP-II at sqrt{s}=196-209 GeV. https://doi.org/10.1140/epjc%2Fs10052-007-0273-z

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