Abstract
We report a new microscopic equation of state (EoS) of pure neutron matter (PNM) at zero temperature using the recent realistic two-body interaction derived in the framework of chiral perturbation theory (ChPT). The EoS is derived using the Brueckner–Bethe–Goldstone quantum many-body theory in the Brueckner–Hartree–Fock approach. We have calculated the EoS of PNM at low and high densities using LO, NLO, N
2
LO, N
3
LO, N
4
LO potentials at three different values of the momentum-space cut-off
Λ
= 450, 500 and 550 MeV. It is found that the EoS is not much affected by the cut-off variations at low densities. Also the binding energy of PNM has been computed within the framework of the Brueckner–Hartree–Fock (BHF) approach plus two-body density-dependent Skyrme potential which is equivalent to three-body forces. The effect of the two-body density-dependent Skyrme potential is to produce a stiffer EoS. This is actually needed to improve the saturation point of symmetric nuclear matter obtained using the two-body
NN
interaction. The results of several microscopic approaches are compared. It is found that the EoS is sensitive to the momentum-space cut-off
Λ
. Also the partial wave contributions to potential energy at the empirical saturation density
ρ
=
0.16
fm
-
3
for different potentials are listed from
1
S
0
to
3
F
3
states. It is found that all contributions are nearly cut-off independent except the ones from
3
P
1
,
3
P
2
,
3
H
4
and
3
F
4
states, which are increasing with the cut-off
Λ
. Actually, the size of these contributions is strongly dependent on the central and tensor components in the
NN
potential. The larger cut-off
Λ
corresponds to harder interactions and gives more repulsive contribution to the
NN
potential at short distance. It leads to smaller binding energy.