title: Search for a fourth-generation quark more massive than the Z0 boson in p&pmacr; collisions at radicals = 1.8 TeV
abstract: We present the results of a search for pair production of a fourth-generation charge -1 / 3 quark (b(')) in sqrt[s] = 1.8 TeV p&pmacr; collisions using 88 pb(-1) of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b(')-->bZ(0) and that the b(') mass is greater than m(Z)+m(b). We studied the decay mode b(')b(');-->Z(0)Z(0)b&bmacr; where one Z0 decays into e(+)e(-) or &mgr;(+)&mgr;(-) and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the sigma(p&pmacr;-->b(')b(');)x[B(b(')-->bZ(0))](2) is established as a function of the b(') mass. We exclude at 95% confidence level a b(') quark with mass between 100 and 199 GeV/c(2) for B(b(')-->bZ(0)) = 100%.
authors.affiliation: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.initials: W
authors.lastname: Trischuk
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authors.initials: S
authors.lastname: Truitt
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authors.lastname: Tseng
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authors.lastname: Turini
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authors.lastname: Ukegawa
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authors.lastname: Valls
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authors.lastname: Velev
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authors.lastname: Vidal
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authors.lastname: Wang
authors.initials: MJ
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authors.lastname: Watanabe
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authors.lastname: Waters
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authors.lastname: Watts
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authors.lastname: Webb
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authors.lastname: Wenzel