  Generalized Parton Distributions (GPDs) provide a dynamical picture of the
nucleon. The exclusive production of $\rho^0$ mesons on a transversely
polarised target is sensitive to the nucleon helicity-flip GPDs $E$ which are
related to the total angular momentum of quarks and gluons. In 2007 and 2010
the COMPASS experiment at CERN collected data by scattering a 160 GeV/c muon
beam off a transversely polarised NH$_3$ target. The final state particles were
detected with the two-stage spectrometer with high resolution tracking. In this
talk new results for the azimuthal asymmetries $A_{\text{UT}}$ and
$A_{\text{LT}}$ are presented.
