Gamow-Teller decay

Thus, in order to understand such environments it is necessary to calculate complete network of the competitions between neutron capture and beta decay as well as their corrections for the thermal population of excited states. With regard to this latter correction it is particularly important to know the low-energy level structure of nuclei away from stability. This structure will affect the beta decay properties differently from the neutron capture properties. In a separate contribution to this conference, [TAK85] we will discuss the corrections for beta decay. Basically this becomes important if a low-lying excited state can undergo a Gamow-Teller allowed decay. The... 

Examples of large-basis shell-model calculations of Gamow-Teller 6-decay properties of specific interest in the astrophysical s-and r- processes are presented. Numerical results are given for i) the GT-matrix elements for the excited state decays of the unstable s-process nucleus "Tc and ii) the GT-strength function for the neutron-rich nucleus 130Cd, which lies on the r-process path. The results are discussed in conjunction with the astrophysics problems. 

Only Gamow Teller (GT) allowed 0-decay is studied in this work as it plays the dominant role in the specified mass range. The experimentally studied nuclei are assumed to be... 

Beta-decay half-lives for the neutron-rich isotopes measured in this experiment are compared with previous measurements when they exist. Theoretical predictions for Gamow-Teller beta decay are also provided for... 

For the nuclei studied in this experiment the dominant decay mode is Gamow-Teller beta decay.Partial halflives corresponding to Gamow-Teller beta decay calculated in a spherical shell model formalism [Bro85] are shown in Table I.The calculated lifetimes are with one exception(17C) all shorter than the measured lifetimes. 

The decay of He to the ground state of Li is superallowed and is the most important evidence for the Gamow-Teller type of coupling in beta-decay. The Fermi allowed decay which would be expected from He to its isobar state at 3.57 MeV in Li is just energetically impossible. No trace of gamma radiation in the He decay has been found, nor has any transition to the 2.189 MeV level (/ = 3 ) been seen. 

In n times forbidden transitions AI=n,n+l and TtjTtf = (—1)". In the region 6 < log ft <9 both allowed and first forbidden P-transitions occur. For example, the P 0" and Na P 3 2 decays are allowed Gamow-Teller transitions, although they have rather large log ft values of 7.9 and 7.4, respectively. Second, third, and fourth forbidden transitions were observed rarely they are mainly in the region 10 < log ft. 

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