Neutron richGa73andAs

Coulomb excitation ofGa73

“…A combination of the results from previous experiments opens the possibility of a 1/2 − , 3/2 − ground-state doublet in 73 Ga. The existence of such a doublet is compatible with the available transfer reaction data as the population of the yrast 1/2 − state is weak compared to the 3/2 − ground state in similar experiments studying 69,71 Ga [4,6,7]. From the energy systematics, there seems to be a more general structural difference between the odd-A gallium isotopes up to 69 Ga 38 and those with 40 neutrons or more (see Fig.…”

“…2(b) it can be seen that the peak originating from the depopulation of the 199-keV state is Doppler-broadened. An excited state with an energy of 198(3) keV was observed previously in the one-proton stripping reaction with L = 3, restricting its spin and parity to 5/2 − , 7/2 − [7]. As this state is populated directly by Coulomb excitation, the spin can be firmly fixed as 5/2 − .…”

“…Considering recent laser spectroscopy data, the ground-state spin was found to be 1/2 − while transfer reactions gave evidence for a 3/2 − state close to the ground state. No evidence for a doublet near the ground state of 73 Ga was obtained from the transfer reaction studies [4][5][6][7][8][9].…”

“…From two-neutron-transfer reaction data, the spin and parity of the 218-keV level are known to be 3/2 − . A state around 495 keV was observed in the 74 Ge(d, 3 He) reaction with L = 3 [7], limiting the spin and parity of this state to 5/2 − or 7/2 − . Data from the 74 Ge(d, 3 He) reaction using polarized deuterons favor a 7/2 − assignment for this state [26].…”

“…The structure of the neutron-rich odd-A gallium isotopes (Z = 31) has been studied in the past by means of β decay [1][2][3], single-and multiparticle transfer reactions [4][5][6][7][8][9], and more recently by deep inelastic reactions [10]. The twoneutron-transfer reaction data suggest a change in structure between 71 Ga 40 and 73 Ga 42 , which is most probably related to the structural difference observed between 72 Ge 40 and 74 Ge 42 (Z = 32), where both the 72 Ge 40 (t,p) 74 Ge 42 and 74 Ge 42 (p,t) 72 Ge 40 reactions strongly populate the excited 0 + state, indicating a shape transition [11].…”