Articles written in Pramana – Journal of Physics

• Properties of pure neutron matter at low and high densities

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-of 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 $\rho$ = 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.

• # Pramana – Journal of Physics

Volume 95, 2021
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019