Heidelberg 2015 – wissenschaftliches Programm
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HK: Fachverband Physik der Hadronen und Kerne
HK 48: Poster
HK 48.21: Poster
Mittwoch, 25. März 2015, 17:00–19:00, C/Foyer
Bound-state β-decay of bare 205Tl81+ — •Bingshui Gao for the FRS-ESR collaboration — GSI, Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt, Germany
Beta decay into bound electron states of the daughter atom (βb−), accompanied by the emission of a monochromatic antineutrino, has been predicted by Daudel et al. However, a noteworthy probability of βb−-decay exists only for highly-charged ions and the experimental storage ring ESR at GSI is a unique tool for investigating βb−-decays. A forthcoming experiment is the determination of the half-life of βb−-decay of bare 205Tl81+, which is related to both the solar pp-neutrino flux and the s-process nucleosynthesis. On the one hand, the LOREX project addresses the relative amount of 205Tl and 205Pb atoms in deep-lying thallium-rich minerals. There 205Pb atoms are generated by the capture of solar pp-neutrinos, with an unprecedented small threshold of only 52 keV. The ratio of 205Pb/205Tl renders the product of the mean pp-solar neutrino flux <φνe> and the neutrino capture cross section σνe. The latter can only be obtained by measuring the half-life of βb−-decay of bare 205Tl81+ because νe-capture andβb−-decay share the same nuclear matrix element. On the other hand, 205Pb is the only purely s-process short-lived radioactivity which gives insight in nucleosynthesis just prior to Sun’s birth. It has been demonstrated that in the stellar environment the production rate of 205Pb in the s-process sensitively depends on both free electron capture of 205Pb and βb−-decay of bare and H-like 205Tl. It is thus desirable to measure the half-life of the βb−-decay of 205Tl81+.