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.


Recent compilations of experimental gross beta-decay properties, i.e. half-lives T1/2 and neutron-emission probabilities (Pn), 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. T1/2 and Pn 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
created 2001 last modified 5 July 2012