Search for a Fourth-Generation Quark More Massive than the Z0 Boson in ppbar Collisions at sqrt(s) = 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 ppbar 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 and that the b' mass is greater than m_Z + m_b. We studied the decay mode b'b'bar -> ZZ b bbar where one Z0 decays into e^+e^- or mu^+ mu^- and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the cross section of ppbar -> b'b'bar times [BR (b' -> bZ)]^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 BR(b' -> bZ) = 100%.

12 pages, 2 figures, submitted to Phys. Rev. Letters on 9/12/99

References in corpus (11)

• Evidence for Top Quark Production in $\bar{p}p$ Collisions at $\sqrt{s}=1.8$ TeV
• Top Quark Production Cross Section
• Quark Singlets: Implications and Constraints
• Minimal SU(5) Resuscitated by Long-Lived Quarks and Leptons
• A Minimal Four-Family Supergravity Model
• Kinematic Evidence for Top Quark Pair Production in $W+$ Multijet Events in $p\bar{p}$ Collisions at $\sqrt{s}$~=~1.8 TeV
• Search for a Fourth Generation Charge -1/3 Quark via Flavor Changing Neutral Current Decay
• Long-Lived Quarks?
• Search for Long-Lived Parents of Z Bosons in pbar-p Collisions at sqrt{s}=1.8 TeV
• Four-Generation Low Energy Supersymmetry with a Light Top Quark
• Realistic SUSY model with four fermion families, natural R parity and ${\nu }_{\tau }$ in the eV Range

Cited by in corpus (22)

• Bounds on Universal Extra Dimensions
• Strong Dynamics and Electroweak Symmetry Breaking
• Beautiful Mirrors and Precision Electroweak Data
• Low Scale Flavor Gauge Symmetries
• Collider aspects of flavour physics at high Q
• From the LHC to Future Colliders
• Flavor Changing Neutral Currents involving Heavy Quarks with Four Generations
• Search for New Particles Leading to Z+jets Final States in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV
• Search for pair production of a new quark that decays to a Z boson and a bottom quark with the ATLAS detector
• Beautiful Mirrors, Unification of Couplings and Collider Phenomenology
• Electroweak phase transition in the MSSM with four generations
• Phenomenological Constraints on Extended Quark Sectors
• String Scale Gauge Coupling Unification with Vector-like Exotics and Non-Canonical U(1)_Y Normalization
• Exotic Q=-1/3 Quark Signatures at High-Energy Hadron Colliders
• Window on Higgs Boson: Fourth Generation $b^{\prime }$ Decays Revisited
• Bounds on the mass of the b' quark, revisited
• Neutral scalar Higgs bosons in the USSM at the LHC
• Measurement of the ttbar Production Cross Section with an in situ Calibration of b-jet Identification Efficiency
• Analysis of a model with a common source of CP violation
• Exotic quark effects on the Higgs sector of the USSM at the LHC
• Could there be a Fourth Generation?
• Proceedings to the Workshops ''What comes beyond the Standard model'' 2000,2001, VOLUME 1: Festschrift dedicated to the 60th birthday of Holger Bech Nielsen