Two-body correlation functions in nuclear matter with neutron-proton condensate
A. A. Isayev
Kharkov Institute of Physics and Technology, 61108 Kharkov, Ukraine
Kharkov National University, 61077 Kharkov, Ukraine
PACS: 21.30.Fe, 21.65.+f, 71.10.Ay
Abstract
The density, spin and isospin correlation functions in
nuclear matter with a neutron-proton condensate are
calculated to study the possible signatures of the BEC-BCS
crossover in low-density region. It is shown that criterion of the
crossover (Phys. Rev. Lett. 95, 090402 (2005)), consisting
in the change of the sign of the density correlation function at
low momentum transfer, fails to describe correctly the
density-driven BEC-BCS transition at finite isospin asymmetry or
finite temperature. As an unambiguous signature of the BEC-BCS
transition, there can be used the presence (BCS regime) or absence
(BEC regime) of the singularity in the momentum distribution of
the quasiparticle density of states.