The discovery of the fourth family at the LHC: what if?

Abstract

The first evidence of new strong interactions may be a sufficiently massive fourth family observed at the LHC. The fourth family masses, of the leptons in particular, are constrained by the electroweak precision data, and this leads to signatures at the LHC that may imply early discovery. We study the implications of this discovery from a bottom-up perspective, where effective 4-fermion operators model the dominant effects of the new dynamics. We identify simple approximate symmetries of these operators that may be required for realistic masses of the third and fourth families. The large top mass for instance is related to the structure of these operators.

15 pages, 1 figure, now matches published version

References in corpus (1)

• Search for Low-Scale Technicolor at the Tevatron

Cited by in corpus (31)

• Models of Yukawa interaction in the two Higgs doublet model, and their collider phenomenology
• Less space for a new family of fermions
• Colored Unparticles
• Electroweak Symmetry Breaking from a Holographic Fourth Generation
• The heavy quark search at the LHC
• An MSSM Extension with a Mirror Fourth Generation, Neutrino Magnetic Moments and LHC Signatures
• Fourth Family Neutrinos and the Higgs Boson
• A fourth generation, anomalous like-sign dimuon charge asymmetry and the LHC
• Approaching a strong fourth family
• Anomalous single production of fourth generation $t^{\prime }$ quarks at ILC and CLIC
• Single Production of Fourth Family Quarks at the LHC
• Search for the Anomalous Interactions of Up-Type Heavy Quarks in $\gamma \gamma$ Collision at the LHC
• Searches for the $t^{\prime }$ of a fourth family
• Dynamics behind the quark mass hierarchy
• Extended Friedberg Lee hidden symmetries, quark masses and CP-violation with four generations
• Single Production of Fourth Family $t^{\prime }$ Quarks at LHeC
• Consequences of a Pati-Salam unification of the electroweak-scale active ${\nu }_R$ model
• Anomalous Single Production of the Fourth Generation Quarks at the LHC
• Production of Single Heavy Charged Leptons at a Linear Collider
• Fourth Generation Leptons and Muon $g-2$
• The accidental Higgs
• The Two Scales of New Physics in Higgs Couplings
• Constraints on fourth generation Majorana neutrinos
• Exclusive $B \rar ρ\ell^+ \ell^-$ Decay in the Standard Model with Fourth--Generation
• Electroweak Symmetry Breaking From Monopole Condensation
• Analysis of the B --> π\ell^+ \ell^- Decay in the Standard Model with Fourth Generation
• New Flavor Interactions at the LHC
• Dynamical symmetry breaking, CP violation, and a Higgs-like particle
• Anomalous Single Production of the Fourth Generation Neutrino at Future ep Colliders
• Gauged $L_e-L_{\mu }-L_{\tau }$ symmetry, fourth generation, neutrino mass and dark matter
• Bounding CKM Mixing with a Fourth Family