Spurious center of mass effects in the finite temperature Hartree-Fock approximation

Abstract

In this paper we study the degree of thermal excitation of the center of mass (CM) in the finite temperature Hartree-Fock (FTHF) approximation to nuclei. For 16O we take two zero-temperature Hartree-Fock solutions of a realistic effective hamiltonian and follow their temperature dependence to T = 5.1 MeV where they merge to a single solution. We find that there is remarkably little thermal excitation of the CM compared to thermal excitation of intrinsic degrees of freedom. Furthermore, since both solutions contain significant spurious CM motion even at zero temperature and since the non-spherical solution is lower, we observe a deformed to spherical “phase transition” in which the CM spuriosity is most probably comparable to that of T = 0.