Warped fermions and precision tests

We analyze the behavior of standard model matter propagating in a slice of ${\mathrm{A}\mathrm{d}\mathrm{S}}_5$ in the presence of infrared-brane kinetic terms. Brane kinetic terms are naturally generated through radiative corrections and can also be present at tree level. The effect of the brane kinetic terms is to expel the heavy Kaluza-Klein (KK) modes from the infrared brane, and hence to reduce their coupling to the localized Higgs field. In a previous work we showed that sizable gauge kinetic terms can allow KK mode masses as low as a few TeV, compatible with present precision measurements. We study here the effect of fermion brane kinetic terms and show that they ameliorate the behavior of the theory for third generation fermions localized away from the infrared brane, reduce the contribution of the third generation quarks to the oblique correction parameters and maintain a good fit to the precision electroweak data for values of the KK masses of the order of the weak scale.