Supersymmetric grand unified theories: Two-loop evolution of gauge and Yukawa couplings
Supersymmetric grand unified theories: Two-loop evolution of gauge and Yukawa couplings
We make a numerical study of gauge and Yukawa unification in supersymmetric grand unified models and examine the quantitative implications of fermion mass Ans\"atze at the grand unified scale. Integrating the renormalization group equations with ${\ensuremath{\alpha}}_{1}({M}_{Z})$ and ${\ensuremath{\alpha}}_{2}({M}_{Z})$ as inputs, we find ${\ensuremath{\alpha}}_{3}({M}_{Z})\ensuremath{\simeq}0.111(0.122)$ for ${M}_{\mathrm{SUSY}}={m}_{t}$ and ${\ensuremath{\alpha}}_{3}({M}_{Z})\ensuremath{\simeq}0.106(0.116)$ for ${M}_{\mathrm{SUSY}}=1$ TeV …