2005/12/15 by Philip Schuster, Philip C. Schuster, Schuster, Philip C. +2 · 5 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/0512189
10 pages, 6 figures, 2 tables
arxiv created 2005/12/15 · openalex publication_date 2005/12/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We examine the use of modified Higgs sectors to address the little hierarchy problem of supersymmetry. Such models reduce weak-scale fine-tuning by allowing lighter stops, but they retain some fine-tuning independent of the Higgs. The modified Higgs sector can also introduce model-dependent tunings. We consider the model-independent constraints on naturalness from squark, gluino, chargino and neutralino searches, as well as the model-dependent tuning in the PQ- and R-symmetric limits of the NMSSM, where cascade decays or additional quartic interactions can hide a Higgs without relying on heavy stops. Obtaining viable electroweak symmetry breaking requires a tuning of ∼ 1-10% in the PQ limit. A large A-term is also necessary to make charginos sufficiently heavy, and this introduces an additional weak-scale tuning of ∼ 10%. The R-symmetric limit requires large marginal couplings, a large singlet soft mass, and a tuning of ∼ 5-10% to break electroweak symmetry. Hiding MSSM-like Higgs states below ≈ 112 GeV requires additional tunings of A-terms at the ∼ 1-10% level. Thus, although the NMSSM has rich discovery potential, it suffers from a unique fine-tuning problem of its own.