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New calculations of gross beta-decay properties for astrophysical
applications ===>
``Speeding-up the classical r-process''

Peter Möller
Theoretical Division, Los Alamos National Laboratory,
New Mexico 87545, USA
Bernd Pfeiffer and Karl-Ludwig Kratz
Institut für Kernchemie, Universität Mainz, Germany

The paper
**New calculations of gross beta-decay properties for astrophysical
applications ===>
``Speeding-up the classical r-process''**
by
Peter Möller, Bernd Pfeiffer, and Karl-Ludwig Kratz,
has been assigned Los Alamos National Laboratory Preprint No LA-UR-02-2919,
and has been submitted for publication.

Abstract:

Recent compilations of experimental gross beta-decay properties,
i.e. half-lives T_{1/2} and neutron-emission probabilities (P_{n}), are compared to
improved global macroscopic-microscopic model predictions. The model combines
calculations within the quasi-particle random-phase approximation (QRPA) for
the Gamow-Teller (GT) part, with an empirical spreading of the QP-strength,
and the gross theory for the first-forbidden (*ff*) part of beta^{-}-decay.
Nuclear masses are either taken from the Audi et al. 1995 data compilation,
when available,
or from the finite-range droplet model (FRDM). In particular for spherical and
neutron-(sub-)magic isotopes, a considerable improvement compared to our
earlier predictions for pure GT-decay [ADNDT 1997] is observed. T_{1/2} and P_{n}
values up to the neutron drip-line have been applied to r-process calculations
within the classical ``waiting-point'' approximation. With the new
nuclear-physics input, a considerable speeding-up of the r-matter flow is
observed, in particular at the r-abundance peaks which are related to magic
neutron-shell closures.

The complete manuscript
is
available for download. The manuscrips has 5 color figures
and is therefore best printed on a color printer.

Another version of the manuscript
with an embellished title page is also
available for download. Even on a powerful color printer
like the Tektronix Phaser 540 the title page may take 15 or so minutes
to be printed.

The beta-decay rates and the production ratios
of final nuclei following beta-delayed neutron-emission
calculated in this model are available in a
data file
with format (I5,I4,F20.5,F8.4,3F7.4).
The quantities tabulated are Z,N,T1/2,P(A),P(A-1),P(A-2)
where T1/2 is the beta-decay half-life in seconds, and P(A-k) is the
probability of producing a final nucleus with mass number A-k
following beta decay and neutron emission.

Page by
Peter Möller

* moller@lanl.gov*

created 2001 last modified 5 July 2012