ANGULAR-CORRELATIONS IN INTERNAL PAIR CONVERSION OF ALIGNED HEAVY-NUCLEI

We calculate the spatial correlation of electrons and positrons emitte d by internal pair conversion of Coulomb excited nuclei in heavy-ion c ollisions. The alignment of the nucleus results in an anisotropic emis sion of the electron-positron pairs that is closely related to the ani sotropic emission of gamma rays. However, the angular correlation in t he case of internal pair conversion displays additional features which provide the possibility for a deeper understanding of the nuclear str ucture. Our results are of particular interest for the electron-positr on coincidence experiments currently analyzed at GSI (Darmstadt) and a t Argonne.