Four Generations: SUSY and SUSY Breaking

Abstract

We revisit four generations within the context of supersymmetry. We compute the perturbativity limits for the fourth generation Yukawa couplings and show that if the masses of the fourth generation lie within reasonable limits of their present experimental lower bounds, it is possible to have perturbativity only up to scales around 1000 TeV. Such low scales are ideally suited to incorporate gauge mediated supersymmetry breaking, where the mediation scale can be as low as 10-20 TeV. The minimal messenger model, however, is highly constrained. While lack of electroweak symmetry breaking rules out a large part of the parameter space, a small region exists, where the fourth generation stau is tachyonic. General gauge mediation with its broader set of boundary conditions is better suited to accommodate the fourth generation.

27 pages, 5 figures

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Cited by in corpus (15)

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• The Impact of a 4th Generation on Mixing and CP Violation in the Charm System
• Four Generations, Higgs Physics, and the MSSM
• Proton stability from a fourth family
• Large mass splittings for fourth generation fermions allowed by LHC Higgs exclusion
• Ultraviolet Completions of Axigluon Models and Their Phenomenological Consequences
• The Need for New Search Strategies for Fourth Generation Quarks at the LHC
• Neutrino Masses and a Fourth Generation of Fermions
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• Semileptonic B to Scalar meson Decays in the Standard Model with Fourth Generation
• A Fourth Chiral Generation And Susy Breaking