APS April Meeting 2014
Volume 59, Number 5
Saturday–Tuesday, April 5–8, 2014;
Savannah, Georgia
Session Y3: Invited Session: R-Process Nucleosynthesis
1:30 PM–3:18 PM,
Tuesday, April 8, 2014
Room: Chatham Ballroom B
Sponsoring
Units:
DNP DAP
Chair: Charles Horowitz, Indiana University
Abstract ID: BAPS.2014.APR.Y3.3
Abstract: Y3.00003 : Hans A. Bethe Prize: Astrophysical, observational and nuclear-physics aspects of r-process nucleosynthesis
2:42 PM–3:18 PM
Preview Abstract
Abstract
Author:
Karl-Ludwig Kratz
(MPI fuer Chemie (Otto-Hahn-Institut) and Univ. Mainz, FB 09, Mainz, Germany)
Guided by the Solar System (S.S.) abundance peaks at A$\simeq$130 and
A$\simeq$195,
the basic mechanisms for the rapid neutron-capture process (the {\it r-process})
have been known for over 50 years. However, even today, all proposed scenarios
and sites face problems with astrophysical conditions as well as with the
necessary nuclear-physics
input. In my talk, I will describe efforts in experimental and theoretical
nuclear-structure
data for modeling today's three groups of r-process {\it ``observables''}, i.e.
the bulk S.S.
isotopic abundances, the elemental abundances in metal-poor halo stars, and
peculiar
isotopic patterns measured in certain cosmic stardust grains. To set a historical
basis, I
will briefly recall our site-independent {\it ``waiting-point''} model, with
superpositions
of neutron-density components and the use of the first global, unified nuclear
input
based on the mass model FRDM(1992). This approach provided a considerable leap
forward in the basic understanding of the required astrophysical conditions, as
well as
of specific shell-structure properties far from stability. Starting in the early
millenium,
the above simple model has been replaced by more realistic, dynamical parameter
studies within the high-entropy wind scenario of core-collapse supernovae, now
with superpositions of entropy (S) and electron-fraction (Y$_e$) components.
Furthermore,
an improved, global set of nuclear-physics data is used today, based on the new
mass
model FRDM(2012). With this nuclear and astrophysics parameter combination, a
new
fit to the S.S. r-abundances will be shown, and its improvements and remaining
deficiencies in terms of underlying shell structure will be discussed.
Concerning the
abundance patterns in metal-poor halo stars, an interpretation of the production
of {\it ``r-rich''} (e.g. CS 22892-052) and {\it ``r-poor''} (e.g. HD 122563)
stars in terms
of different (Y$_e$), S combinations will be presented. Finally, for the third
group of
{\it ``r-observables''}, a possible origin of the anomalous Xe-H pattern in
presolar
nanodiamonds by the {\it ``main''} component of a {\it ``cold''} r-process is
suggested.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.APR.Y3.3