  We investigate the phenomenological viability of a very light bottom squark,
with a mass less than half of the Z boson mass. The decays of the Z and Higgs
bosons to light sbottom pairs are, in a fairly model independent manner,
strongly constrained by the precision electroweak data and Higgs signal
strength measurements, respectively. These constraints are complementary to
direct collider searches, which depend in detail on assumptions regarding the
superpartner spectrum and decays of the sbottom. In particular, if the lightest
sbottom has a mass below about 15 GeV, compatibility with these measurements is
possible only in a special region of parameter space in which the couplings of
the lightest sbottom to the Z and Higgs are suppressed. In this region, the
second sbottom is predicted to be lighter than about 300 GeV and can also be
searched for directly at the LHC. We also survey relevant collider searches for
canonical scenarios with a bino, gravitino, or singlino LSP in the compressed
and stealth kinematic regimes and provide suggestions to cover remaining open
regions of parameter space.
