Sensitivity of nuclear statistical equilibrium to nuclear uncertainties during stellar core collapse. (arXiv:1811.10198v1 [nucl-th])
<a href="http://arxiv.org/find/nucl-th/1/au:+Furusawa_S/0/1/0/all/0/1">Shun Furusawa</a>
I have systematically investigated the equations of state (EOSs) in nuclear
statistical equilibrium under thermodynamic conditions relevant for core
collapse of massive stars by varying the bulk properties of nuclear matter, the
mass data for neutron-rich nuclei, and the finite-temperature modifications of
the nuclear model. It is found that the temperature dependence of the nuclear
free energies has a significant impact on the entropy and nuclear composition,
which affect the dynamics of core-collapse supernovae. There is a little
influence from the bulk properties and the mass data. For all models, common
nuclei that are likely to contribute to core-deleptonization are those near
$Zapprox30$ and $Napprox50$. A model with a semi-empirical expression for
internal degrees of freedom, however, overestimates the number densities of
magic nuclei with $Napprox50$ and $82$, while a model, in which nuclear shell
effects are not considered, underestimates the number densities of heavy
nuclei, and especially of the magic nuclei. Other models, which include the
temperature dependence of shell effects in the internal degrees of freedom
and/or in the nuclear internal free energy, indicate that the difference in
population between magic nuclei and non-magic nuclei disappears as the
temperature increases. The construction of complete statistical EOS will
require further theoretical and experimental studies of medium-mass,
neutron-rich nuclei with proton numbers 25$-45 and neutron numbers 40-85.
I have systematically investigated the equations of state (EOSs) in nuclear
statistical equilibrium under thermodynamic conditions relevant for core
collapse of massive stars by varying the bulk properties of nuclear matter, the
mass data for neutron-rich nuclei, and the finite-temperature modifications of
the nuclear model. It is found that the temperature dependence of the nuclear
free energies has a significant impact on the entropy and nuclear composition,
which affect the dynamics of core-collapse supernovae. There is a little
influence from the bulk properties and the mass data. For all models, common
nuclei that are likely to contribute to core-deleptonization are those near
$Zapprox30$ and $Napprox50$. A model with a semi-empirical expression for
internal degrees of freedom, however, overestimates the number densities of
magic nuclei with $Napprox50$ and $82$, while a model, in which nuclear shell
effects are not considered, underestimates the number densities of heavy
nuclei, and especially of the magic nuclei. Other models, which include the
temperature dependence of shell effects in the internal degrees of freedom
and/or in the nuclear internal free energy, indicate that the difference in
population between magic nuclei and non-magic nuclei disappears as the
temperature increases. The construction of complete statistical EOS will
require further theoretical and experimental studies of medium-mass,
neutron-rich nuclei with proton numbers 25$-45 and neutron numbers 40-85.
http://arxiv.org/icons/sfx.gif
