  A minimal supersymmetric brane-world model is presented which has: i) zero
classical four-dimensional vacuum curvature, despite the large naive vacuum
energy due to contributions from Standard Model particles; ii) one-(bulk)-loop
quantum corrections to the vacuum energy with a size set by the radius of the
extra-dimensional spheroid. These corrections are technically natural because a
BPS-like relation between the brane tension and R-charge---which would have
preserved (half of) the bulk supersymmetry---is violated by the requirement
that the stabilizing R-symmetry gauge flux be quantized. The extra-dimensional
geometry is similar to previous rugby-ball geometries, but is simpler in that
there is only one brane and so fewer free parameters. Although the sign of the
renormalized vacuum energy ends up being the unphysical one for this model (in
the limit considered here, where the massive bulk loop is the leading
contribution), it serves as an illustrative example of the relevant physics.
