Effect of multiparticle correlations on the stability of electron-positron clusters

The total energy of electrically neutral electron-positron clusters with closed shells containing different numbers of pairs has been calculated. The inclusion of multiparticle correlations in the random phase approximation with exchange has allowed the reduction of the energy per pair of particles below the energy per dipositronium molecule. The calculations have revealed the region of the minimum of the total energy per pair of particles at the numbers of pairs in the range of 20 to 40, which assumingly correspond to the most stable electron-positron droplets