  Large transverse single spin asymmetries (SSA) were measured for pions
produced in pp-collisions up to RHIC energies. Sizeable SSA were also found in
semi-inclusive deep inelastic scattering (SIDIS). Theory can explain such spin
effects by going beyond collinear leading-twist perturbative QCD (pQCD) to
include transverse momentum dependent (TMD) distribution and fragmentation
functions. One of the most interesting TMDs is the Sivers function, which
provides information on the correlation between the transverse spin of the
nucleon and the transverse momentum distributions of the partons in the
nucleon. It is particularly intriguing that theory predicts the Sivers function
will change sign from SIDIS to Drell-Yan (DY) production. ANDY is aiming to
test that prediction and to establish requirements for future upgrades at RHIC
to study DY production. The experiment configuration, achievements to date,
status and plans are discussed.
