Within the context of traditional logarithmic grand unification at $M_{\mathrm{G}\mathrm{U}\mathrm{T}}\approx {10}^{16}\mathrm{G}\mathrm{e}\mathrm{V}$, we show that it is nevertheless possible to observe certain GUT states such as $X$ and $Y$ gauge bosons at lower scales, perhaps even in the TeV range. We refer to such states as “GUT precursors.” These states offer an interesting alternative possibility for new physics at the TeV scale, and could be used to directly probe GUT physics even though the scale of gauge coupling unification remains high. Our results also give rise to a Kaluza-Klein realization of nontrivial fixed points in higher-dimensional gauge theories.

• Received 26 February 2003

DOI:https://doi.org/10.1103/PhysRevLett.91.061601