Four-fermion contact terms in charged current processes and large extra dimensions

We study the bounds that can be obtained on four-fermion contact terms from the experimental data for ${e}^{+}\stackrel{\ensuremath{\rightarrow}}{p}\overline{\ensuremath{\nu}}X$ obtained at DESY HERA and $p\overline{p}\ensuremath{\rightarrow}{e}^{\ifmmode\pm\else\textpm\fi{}}$ measured at the Fermilab Tevatron. We compare these bounds with the ones available in the literature. Finally, we apply these results to study the compactification radius in theories with large extra dimensions and we obtain the bound ${M}_{c}g~3.3 \mathrm{TeV}.$