Kaluza-Klein mesons in universal extra dimensions

In models with universal extra dimensions, the isosinglet Kaluza-Klein (KK) quarks ($q^1$) have very narrow widths, of $O(5–10)\mathrm{MeV}$, and will thus hadronize. Studies of KK quarkonia (${\overline{q}}^1{q}^1$) show very sharp resonances and dramatic signatures at the linear collider. In this Brief Report, we consider the possibility of detecting KK mesons, $({\overline{q}}^{1}q)$, and show that detection at a linear collider is unlikely.