2 research outputs found
Predictions of and in an Asymptotically Non-Free Theory
We discuss an extention of the Minimal Supersymmetric Standard Model (MSSM)
with the 4th and anti-4th generations which have
invariant masses. Due to the the extra generations, all three running gauge
couplings become asymptotically non--free while preserving gauge coupling
unification at the GUT scale. We show that due to the asymptotically non--free
character of the gauge couplings: (1) the top and bottom Yukawa couplings are
strongly focused onto infrared fixed points as they are evolved down in scale
making their values at \mu=\mz insensitive to their initial values at
\mu=\mgut; (2) the model predicts \R(\mz) \equiv Y_b/Y_\tau |_{\mu
=\mz}\approx 1.8, which is consistent with the experimental value provided we
take the ratio of Yukawa couplings at the GUT scale to be \R(\mgut) =
Y_b/Y_\tau |_{\mu = \mgut} = 1/3; (3) the mass prediction comes out to be
\mt\approx 180\,\GeV which is also consistent with experiment.Comment: 20 pgs. 7 figures. Latex2e. othersym.sty, suceqn.sty include