9 research outputs found
Ion-Ion Correlation Effect on the Neutrino-Nucleus Scattering in Supernova Cores
We calculate the ion-ion correlation effect on the neutrino-nucleus
scattering in supernova cores, which is an important opacity source for the
neutrinos and plays a vital role in the supernova explosion. In order to
calculate the ion-ion correlation effect we use the results of the improved
hypernetted-chain method calculations of the classical one-component plasma. As
in the preceding studies on this effect, we find a dramatic decrease of the
effective neutrino-nucleus scattering cross section for relatively low energy
neutrinos with E < 20MeV. As a matter of fact, our calculation shows a much
more dramatic reduction of the effective neutrino-nucleus scattering cross
section for the low energy neutrinos with E < 10MeV than the results of
Horowitz. Therefore, the ion-ion correlation effect will be more important than
has hitherto been recognized. We present an accurate analytic fitting formula
that summarizes our numerical results. This fitting formula will facilitate the
application of the present results to the supernova explosion simulations.Comment: 10 pages, 2 figures, 1 subroutine, published in ApJ 611, 1041-1044
(2004
Enhancement of Resonant Thermonuclear Reaction Rates in Extremely Dense Stellar Plasmas
The enhancement factor of the resonant thermonuclear reaction rates is
calculated for the extremely dense stellar plasmas in the liquid phase. In
order to calculate the enhancement factor we use the screening potential which
is deduced from the numerical experiment of the classical one-component plasma.
It is found that the enhancement is tremendous for white dwarf densities if the
^{12}C + ^{12}C fusion cross sections show resonant behavior in the
astrophysical energy range. We summarize our numerical results by accurate
analytic fitting formulae.Comment: 13 pages, 3 figures, accepted for publication in ApJ, replaced with
revised versio
Screening Corrections to the Electron Capture Rates in Dense Stars by the Relativistically Degenerate Electron Liquid
We calculate the screening corrections to the electron capture rates in dense
stars by the relativistically degenerate electron liquid. In order to calculate
the screening corrections we adopt the linear response theory which is widely
used in the field of solid state physics and liquid metal physics. In
particular, we use the longitudinal dielectric function for the
relativistically degenerate electron liquid derived by Jancovici. We calculate
the screening potential at the position of the nucleus. By using this screening
potential one can calculate the screening corrections to the electron capture
rates. We will present accurate analytic fitting formulae which summarize our
numerical results. These fitting formulae will facilitate the application of
the present results. The screening corrections to the electron capture rates
are typically a few percent.Comment: uses AAS LaTeX macro package (Ver. 5.0), 8 pages, 2 tables, 4
figures, 2 subroutines, published in ApJ 579, 380-385 (2002