The one-body momentum distribution of nuclear matter at finite temperature

The one-body momentum distribution of nuclear matter at finite temperature, n(k), is evaluated by using the cluster expansion theory for the occupation probability. The lowest order constrained variational (LOCV) method at finite temperature is used to calculate the correlation functions. The input nucleon–nucleon interactions are the Nijmegen-Reid93 and Av18 as well as Reid68 and Δ-Reid soft core, phenomenological potentials. The gap in n(k) at the Fermi surface is found to be about 97 per cent comparing to 1.0 for the noninteracting Fermi gas model at zero temperature and it is shown to decrease by increasing the temperature. It is also demonstrated that the high-momentum tail of n(k) gets larger as we increase the temperature and the application of different interactions do not have dramatic effect on its behavior.