  After an introduction recalling that we expect low energy supersymmetry to be
part of our description of nature because of considerable indirect evidence and
successful predictions, and a discussion of the essential role of data for
formulating and testing string theory, these lectures focus on the role of the
supersymmetry soft-breaking Lagrangian in connecting experiment and string
theory. How to measure tan$\beta$ and the soft parameters is examined via a
number of applications, and the difficulty of measuring tan$\beta$ at hadron
colliders is explained. In each case the important role of soft phases is made
explicit, and the true number of parameters is counted. Applications include
the chargino and neutralino sectors, the Higgs sector and how its results
change when phases are included, measuring the (relative) gluino phase, CP
violation in K and B systems and whether all CP violation can be due to soft
phases, how to learn if the LSP is the cold dark matter of the universe, and
baryogenesis. It is emphasized that the success of supersymmetry in explaining
the breaking of electroweak symmetry is probably its most important
achievement, and implications of that explanation for superpartner masses are
shown. Combining many of these considerations, a further application argues
that a lepton collider of total energy 600 GeV with a polarized beam is one we
can be confident will do important physics even after LHC. The question of the
origins of CP violation, whether the CKM phase can be zero, and the possibility
that the soft phases can tell us about compactification and supersymmetry
breaking are discussed. Some of the applications and issues are examined in a
D-brane based model that can describe the usual collider and dark matter
phenomenology, and includes phases and CP violation as well.
