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

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

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 sign...

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Bibliografiske detaljer
Main Authors: Abdallah, J, Abreu, P, Adam, W, Adzic, P, Albrecht, T, Alemany-Fernandez, R, Allmendinger, T, Allport, P, Amaldi, U, Amapane, N, Amato, S, Anashkin, E, Andreazza, A, Andringa, S, Anjos, N, Antilogus, P, Apel, W, Arnoud, Y, Ask, S, Asman, B, Augustin, J, Augustinus, A, Baillon, P, Ballestrero, A, Bambade, P
Format: Journal article
Sprog:English
Udgivet: 2007
Beskrivelse
Summary: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 RCKM = | Vtb′Vtb/Vcb′|, where V cb′, Vtb′ and Vtb are elements of the extended CKM matrix. © Springer-Verlag Berlin Heidelberg 2007.

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