  We study baryon-number-violating processes, including proton and bound
neutron decays and $n-\bar n$ oscillations, in a left-right-symmetric (LRS)
model in which quarks and leptons have localized wavefunctions in extra
dimensions. In this model we show that, while one can easily suppress
baryon-number-violating nucleon decays well below experimental bounds, this
does not suppress $n-\bar n$ transitions, which may occur at levels comparable
to current limits. This is qualitatively similar to what was found in an
extra-dimensional model with a Standard-Model low-energy effective field theory
(SMEFT). We show that experimental data imply a lower limit on the mass scale
$M_{n \bar n}$ characterizing the physics responsible for $n-\bar n$
oscillations in the LRS model that is significantly higher than in the
extra-dimensional model using a SMEFT and explain the reason for this. Our
results provide further motivation for new experiments to search for $n - \bar
n$ oscillations.
