Shape study of the N=Z and waiting-point nucleus 72Kr via beta decay

by Jose Antonio Briz Monago (Universidad Complutense (ES))

Thursday 6 Mar 2014, 14:30 → 15:30 Europe/Zurich

26-1-022 (CERN)

The N=Z nucleus ⁷²Kr is situated in the mass region around A=70, where strong deformations and shape coexistence have been found. From the astrophysical point of view, ⁷²Kr is interesting as it is a waiting-point nucleus, i.e. the next step in the rp-process, ⁷³Rb, is unbound and, as a consequence, the competition between two-proton capture and beta-decay occurs when the process reaches ⁷²Kr. For this reason, a good knowledge of its beta-decay properties such as B(GT) distribution and level lifetimes are of vital importance for astrophysical calculations. From the nuclear structure point of view, ⁷²Kr is an interesting case of an exotic nucleus whose shape (in the g.s.) has been predicted to be oblate and can be inferred by means of beta-decay studies.
The use of the Total Absorption Spectroscopy (TAS) technique has previously shown that information on the shapes of the ground states of neighbouring nuclei such as ⁷⁶Sr and ⁷⁴Kr can be obtained. With the same spirit, a complete study of the ⁷²Kr decay was performed here at ISOLDE using the “Lucrecia” TAS spectrometer to obtain the B(GT) distribution in the full Q- window.
I will present the experimental study performed and the comparison of the experimental B(GT) distribution with highly performing mean field calculations in order to shed light on the deformation of the ground state of ⁷²Kr. 
 

Slides JoseBriz_Seminar_2014.pdf