The alpha-particle in nuclear matter

Among the light nuclear clusters the alpha-particle is by far the strongest bound system and therefore expected to play a significant role in the dyna mics of nuclei and the phases of nuclear matter. To systematically study th e properties of the alpha-particle we have derived an effective four-body e quation of the Alt-Grassberger-Sandhas (AGS) type that includes the dominan t medium effects, i.e. self energy corrections and Pauli-blocking in a cons istent way. The equation is solved utilizing the energy dependent pole expa nsion for the subsystem amplitudes. We find that the Mott transition of an alpha-particle at rest differs from that expected from perturbation theory and occurs at approximately 1/10 of nuclear matter densities. (C) 2000 Else vier Science B.V. All rights reserved.