We explore the possibility of unification of gauge couplings near the Planck scale in models of extended technicolor. We observe that models of the form G×SU(3)c×SU(2)L×U(1)Y cannot be realized, due to the presence of massless neutral Goldstone bosons (axions) and light charged pseudo Goldstone bosons; thus, unification of the known forces near the Planck scale cannot be achieved. The next simplest possibility, G×SU(4)PS×SU(2) L×U(1)T3R, cannot lead to unification of the Pati-Salam and weak gauge groups near the Planck scale. However, superstring theory provides relations between couplings at the Planck scale without the need for an underlying grand-unified gauge group, which allows unification of the SU(4)PS and SU(2)L couplings.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)