Searches for new quarks and leptons produced in Z -boson decay

Journal Article · Mon Nov 27 04:00:00 EST 1989 · Physical Review Letters; (USA)

DOI:https://doi.org/10.1103/PhysRevLett.63.2447· OSTI ID:5122846

Abrams, G S; Adolphsen, C E; Averill, D; Ballam, J; Barish, B C; Barklow, T; Barnett, B A; Bartelt, J; Bethke, S; Blockus, D; Bonvicini, G; Boyarski, A; Brabson, B; Breakstone, A; Bulos, F; Burchat, P R; Burke, D L; Cence, R J; Chapman, J; Chmeissani, M ; Cords, D; Coupal, D P; Dauncey, P; DeStaebler, H C; Dorfan, D E; Dorfan, J M; Drewer, D C; Elia, R; Feldman, G J; Fernandes, D; Field, R C; Ford, W T; Fordham, C; Frey, R; Fujino, D; Gan, K K; Gero, E; Gidal, G ^[1]

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1. Lawrence Berkeley Laboratory and Department of Physics University of California, Berkeley, California 94720 (US)

We have searched for events with new-particle topologies in 390 hadronic {ital Z} decays with the Mark II detector at the SLAC Linear Collider. We place 95%-confidence-level lower limits of 40.7 GeV/{ital c}{sup 2} for the top-quark mass, 42.0 GeV/{ital c}{sup 2} for the mass of a fourth-generation charge {minus}(1/3) quark, and 41.3 GeV/{ital c}{sup 2} for the mass of an unstable Dirac neutral lepton.

• DOE Contract Number: AC02-84ER40125; AC03-76SF00098; AC02-76ER01112; AC03-76SF00515
• OSTI ID: 5122846
• Journal Information: Physical Review Letters; (USA), Journal Name: Physical Review Letters; (USA) Vol. 63:22; ISSN PRLTA; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
645102 -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATOR FACILITIES
ACCELERATORS
ANNIHILATION
BASIC INTERACTIONS
BOSONS
BRANCHING RATIO
ELECTROMAGNETIC INTERACTIONS
ELECTRON-POSITRON INTERACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
GEV RANGE
GEV RANGE 10-100
INTERACTIONS
INTERMEDIATE BOSONS
INTERMEDIATE VECTOR BOSONS
LEPTON-LEPTON INTERACTIONS
LEPTONS
LINEAR ACCELERATORS
MASS
MONTE CARLO METHOD
NEUTRAL-CURRENT INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
POSTULATED PARTICLES
QUARKS
STANFORD LINEAR COLLIDER
TOP PARTICLES
Z NEUTRAL BOSONS