Speaker
Description
Recent measurements performed at the GSI facilities have experimentally determined the value for the rate of 205Tl bound-state beta decay. This in turn allows to ascertain the nuclear transition matrix element to the first excited state of 205Pb. This information plays a crucial role in a twofold way.
On one hand, the bound-state beta decay of 205Tl could counter balance the 205Pb electron capture and keep the 205Pb production high during s-process nucleosynthesis, affecting the 205Pb/204Pb ratio and clarify the plausibility for the source of the live 205Pb in the early Solar System.
On the other hand, the capture of solar pp-neutrinos (0≤Eν≤420 keV) allows the transmutation of 205Tl nuclei into 205Pb. The energy threshold for this reaction is Eν≥52 keV, by far the smallest threshold for any known neutrino-induced nuclear reaction. The nuclear transition matrix element to the first excited state of 205Pb can be determined from the one of the bound-state beta decay of 205Tl to this state as the dominant contribution to the nuclear transition matrix is the same.
This work is funded by SFB 1245, Institute für Kernphysics, TU Darmstadt.
