The Gamow-Teller strength distribution covering the entire β-decay window, up to 10.312(4) MeV, of Ga80g+m was measured for the first time in photofission of UCx induced by a 50 MeV electron beam. The new data show significant enhancement in the high-energy region with a jump structure. Simultaneously, the γ deexciting behavior of β-populated states presents a competition between deexcitation to 21+[β2=0.155(9)] and to 22+[β2=0.0530.0090.008)] in Ge80. To understand these data, we performed a realistic shell-model calculation and systematic analysis of logft ratios between precursors' β decay to 22+ and to 21+ of Ga isotopes. We conclude that these phenomena evidence simultaneous impacts of nuclear shell structure and collectivity on B(GT) distribution and therefore the half-life of the precursor.
Simultaneous impacts of nuclear shell structure and collectivity on β decay: Evidence from Ga49 80
De Gregorio G.;Mancino R.;Coraggio L.;Itaco N.;
2025
Abstract
The Gamow-Teller strength distribution covering the entire β-decay window, up to 10.312(4) MeV, of Ga80g+m was measured for the first time in photofission of UCx induced by a 50 MeV electron beam. The new data show significant enhancement in the high-energy region with a jump structure. Simultaneously, the γ deexciting behavior of β-populated states presents a competition between deexcitation to 21+[β2=0.155(9)] and to 22+[β2=0.0530.0090.008)] in Ge80. To understand these data, we performed a realistic shell-model calculation and systematic analysis of logft ratios between precursors' β decay to 22+ and to 21+ of Ga isotopes. We conclude that these phenomena evidence simultaneous impacts of nuclear shell structure and collectivity on B(GT) distribution and therefore the half-life of the precursor.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
