  Extensions of the Standard Model featuring a warped extra dimension
compactified on an $S^1/\mathbb{Z}_2$ orbifold, in which the fermions and gauge
bosons live in the bulk of the fifth dimension, offer one of the most
compelling mechanisms for addressing both the hierarchy problem and the flavor
puzzle of the Standard Model. However, the five-dimensional mass terms of bulk
fermions must be odd functions on the orbifold, and as such they should be
described by a field depending on the coordinate of the extra dimension. We
demonstrate the feasibility of dynamically generating these fermion bulk masses
with a bulk scalar field in warped extra dimensions. The bulk scalar acquires a
vacuum expectation value, which is odd under the orbifold symmetry and gives
rise to the fermion bulk masses through non-universal Yukawa-like interactions.
Like in the conventional Randall-Sundrum setup, the localization of the
different fermion zero modes along the extra dimension naturally explains the
observed flavor structure and four-dimensional mass hierarchy of the SM
fermions. We study the phenomenological implications of the backreaction on the
metric and the modified fermion profiles due to the bulk scalar field on
electroweak precision and flavor observables. Using up-to-date data, we show
that the contributions to the $S$, $T$, and $\epsilon_K$ parameters require the
mass of the first Kaluza-Klein gluon resonance to be of order 14 and 10 TeV in
the minimal and the custodial model, respectively, regardless of the effect of
the backreaction. Furthermore, effective flavor-changing interactions among the
SM fermions induced by the bulk scalar are discussed. We also comment on the
potential impact of the Higgs portal interaction of the bulk scalar on the
couplings of the Higgs boson.
