  We demonstrate that the 8 multipole parameters describing the spin state of
the $Z$ boson are able to disentangle known $Z$ production mechanisms and
signals from new physics at the LHC. They can be extracted from appropriate
asymmetries in the angular distribution of lepton pairs from the $Z$ boson
decay. The power of this analysis is illustrated by (i) the production of $Z$
boson plus jets; (ii) $Z$ boson plus missing transverse energy; (iii) $W$ and
$Z$ bosons originating from the two-body decay of a heavy resonance.
