PROBING HADRONIC POLARIZATIONS WITH DILEPTON ANISOTROPIES

We investigate the production of e(+)e(-) pairs from p + Be and nucleu s-nucleus collisions from 2 GeV/A to 200 GeV/A within a covariant tran sport approach and focus on the dilepton angular anisotropies as a fun ction of the dilepton invariant mass. Whereas the low mass regime yiel ds information about the Dalitz decays of the Delta, eta and omega, ab ove M approximate to 0.5 GeV the angular anisotropies provide addition al information about pi(+)pi(-) --> rho(0) --> e(+)e(-) channel in the medium. The anisotropy coefficient is found to change its sign for M > 0.5 GeV in case of nucleus-nucleus reactions when increasing the bom barding energy from 2 GeV/A to 200 GeV/A which sheds some light on the pi pi --> rho dynamics.