2007/03/05 by Hiroyuki Abe, Hiroyuki Abé, Tatsuo Kobayashi +1 · 3 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.76.015002
published as Phys.Rev.D76:015002,2007 · 17 pages, 29 figures
arxiv created 2007/03/05 · openalex publication_date 2007/07/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We study, in a bottom-up approach, the fine-tuning problem between soft supersymmetry (SUSY) breaking parameters and the \ensuremathμ term for the successful electroweak symmetry breaking in the minimal supersymmetric standard model. It is shown that certain ratios among nonuniversal gaugino masses at the grand unified theory (GUT) scale are necessary to reduce fine-tuning. In addition, when all the gaugino masses are regarded as independent ones in their origins, a small gluino mass M3\ensuremath\lesssim120 GeV and a nonvanishing A term At\ensuremath∼O(M3) associated with top squarks are also required at the GUT scale as well as the nonuniversality. On the other hand, when we consider some UV theory, which fixes ratios of soft SUSY breaking parameters as certain values aside from the overall magnitude, heavier spectra are allowed. It is favored that the gluino and W-ino masses are almost degenerate at the weak scale, while a wider region of b-ino mass is favorable.