Nuclei in the Cosmos - IX

Session

11 Nuclear theory in astrophysics

29 Jun 2006, 08:30

CERN, Geneva

Conveners

11 Nuclear theory in astrophysics

• Friedrich-Karl Thielemann (Basel University)

260. Direct Reactions in/for Nuclear Astrophysics

Carlos Bertulani (Department of Physics, University of Arizona, Tucson, AZ)

29/06/2006, 08:30

Nuclear theory in astrophysics

Invited

Precise nuclear reaction rates are needed for a detailed description of the production of elements in primordial nucleosynthesis and during the hydrostatic burning of stars to constrain the astrophysical models. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies [1]. In recent years several indirect methods have been...

104. Cross sections of light-ion reactions calculated from ab initio wave functions

Christian Forssén (Lawrence Livermore National Laboratory)

29/06/2006, 09:00

Nuclear theory in astrophysics

Oral contribution

I will discuss present attempts to employ many-body nuclear structure information in nuclear reaction calculations. The foundation of our approach is the ab initio no-core shell model (NCSM), which is a well-established theoretical framework aimed at an exact description of nuclear structure starting from high-precision interactions between the nucleons. We are now able to extract...

258. Nuclear models for light systems

Pierre Descouvemont (Physique Nucléaire Théorique et Physique Mathématique)

29/06/2006, 09:20

Nuclear theory in astrophysics

Invited

First we present general properties of low-energy reactions between light nuclei. Different theoretical approaches are briefly described. We present recent results on the 18F(p,a)15O reaction, obtained in a microscopic cluster model. We point out that some 1/2+ resonances, generally disregarded, may play a role. The spectroscopic properties of 19Ne, and charge symmetry between 19Ne and...

70. Modified Nuclear Lifetime in Hot Dense Plasmas

Gilbert GOSSELIN (Comissariat a l'energie atomique (CEA))

29/06/2006, 09:50

Nuclear theory in astrophysics

Oral contribution

In hot dense plasmas, the electronic environment in the immediate vicinity of the nucleus is modified, and thus, the plasma conditions influence key processes driving the lifetime of a nuclear level [1]. A correct lifetime prediction requires every deexcitation process to be evaluated jointly with its corresponding excitation process. For heavy nuclei, the nuclear lifetime of discrete...

212. Enhanced electron screening in nuclear reactions and radioactive decays

Konrad Czerski (Institute of Physics, University of Szczecin, Szczecin, Poland)

29/06/2006, 10:10

Experiments in nuclear astrophysics

Oral contribution

In recent years, an enhanced electron screening in metallic environments has been demonstrated by many groups in experimental investigations of low-energy nuclear reactions. Similarly, first radioactive decay experiments in metallic materials have been performed to possibly observe an alteration of the decay constant due to electron screening. Both kinds of experiments are of fundamental...