Nanosecond-Scale Proton Emission from Strongly Oblate-Deformed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Lu</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>149</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
K. Auranen, A. D. Briscoe, L. S. Ferreira, T. Grahn, P. T. Greenlees, A. Herzáň, A. Illana, D. T. Joss, H. Joukainen, R. Julin, H. Jutila, M. Leino, J. Louko, Minna‐Liisa Luoma, E. Maglione, J. Ojala, R. D. Page, J. Pakarinen, P. Rahkila, J. Romero, P. Ruotsalainen, M. Sandzelius, J. Sarén, A. Tolosa-Delgado, J. Uusitalo, G. Zimba
Abstract
Using the fusion-evaporation reaction ^{96}Ru(^{58}Ni,p4n)^{149}Lu and the MARA vacuum-mode recoil separator, a new proton-emitting isotope ^{149}Lu has been identified. The measured decay Q value of 1920(20) keV is the highest measured for a ground-state proton decay, and it naturally leads to the shortest directly measured half-life of 450_{-100}^{+170} ns for a ground-state proton emitter. The decay rate is consistent with l_{p}=5 emission, suggesting a dominant πh_{11/2} component for the wave function of the proton-emitting state. Through nonadiabatic quasiparticle calculations it was concluded that ^{149}Lu is the most oblate deformed proton emitter observed to date.