Enhanced binding and cold compression of nuclei due to admixture of   antibaryons
  We discuss the possibility of producing a new kind of nuclear system by putting a few antibaryons inside ordinary nuclei. The structure of such systems is calculated within the relativistic mean--field model assuming that the nucleon and antinucleon potentials are related by the G-parity transformation. The presence of antinucleons leads to decreasing vector potential and increasing scalar potential for the nucleons. As a result, a strongly bound system of high density is formed. Due to the significant reduction of the available phase space the annihilation probability might be strongly suppressed in such systems. 
T. Buervenich, I. N. Mishustin, L. M. Satarov, J. A. Maruhn, H.   Stoecker, and W. Greiner