1994/08/12 by J. Lopez, J. A. López, Lopez, J.
Physics and Astronomy · #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9408279
CTP-TAMU-39/94, 20 pages, 8 figures included as uuencoded file. Complete postscript file with embedded figures (0.687MB) is available via anonymous ftp from hplaa02.cern.ch /pub/lopez/Erice94.ps
arxiv created 1994/08/12 · arxiv updated 2009/11/30
I review the theoretical expectactions for the top-quark mass in a variety of models: the Standard Model, unified models (GUTs), low-energy supersymmetric models (SUSY), unified supersymmetric models (SUSY GUTs), supergravity models, and superstring models. In all instances I consider the constraints on the top-quark mass which arise by demanding that these theories be weakly interacting. This assumption is quantified by the use of partial-wave unitarity or triviality. The resulting upper bounds on the top-quark mass are most stringent in SUSY GUTs models (m\rm polet\lsim200sinβ\GeV). I also discuss a class of SU(5)× U(1) superstring models where m\rm polet∼(170-195)\GeV is predicted. I conclude that experimental determinations of the top-quark mass can be \em naturally understood in SUSY GUTs and superstring models. (Lecture presented at the International School of Subnuclear Physics, 32nd Course: From Superstring to Present-Day Physics, Erice--Sicily: July 3--11, 1994.)