
We study an extension of the standard model with one latticized extra dimension accessible to all fields. The model is characterized by the size of the extra dimension and the number of sites, and contains a tower of massive particles. At energies lower than the mass of the new particles there are no treelevel effects. Therefore, bounds on the scale of new physics can only be set from oneloop processes. We calculate several observables sensitive to loopeffects, such as the ρ parameter, b→sγ, Z→bb¯, and the B0⇌B¯0 mixing, and use them to set limits on the lightest new particles for different number of sites. It turns out that the continuous result is rapidly reached when the extra dimension is discretized in about 10 to 20 sites only. For small number of sites the bounds placed on the usual continuous scenario can be reduced by roughly a factor of 10%25%, which means that the new particles can be as light as 320GeV. Finally, we briefly discuss an alternative model in which fermions do not have additional modes.
