Quadrupole deformation of 12Be studied by proton inelastic scattering

Collectivity evolution in the neutron-rich Pd isotopes toward theN=82shell closure

“…For example, the 31,32 Na isotopes were found to have abnormally high masses [1], while for 32 Mg a low first 2 + energy [2] together with a large γ -ray transition probability [3] were found despite its location along the N = 20 shell closure. Similar magicity losses were found around N = 8 [4][5][6] and N = 28 [7][8][9].…”

Study of 14Be with core excitation

“…The same parameters are assumed in the spin-orbit potential. Although the 12 Be deformation has been estimated as |β| = 0.728 ± 0.084 [15], we carry out calculations for the full range of the deformation parameter β ∈ [−1 : 1].…”

“…Fortune et al [14] reported five low-lying states of 12 Be with E x = 0.0(0 + ), 2.1(2 + ), 2.7(0 + ), 4.6(2 + ) and 5.7(4 + ) MeV, where the spin assignments of the last three states are only tentative. In recent years much evidence has been accumulated that 12 Be does not have a good N = 8 neutron closed shell [15][16][17]. Iwasaki et al [15] observed a strong excitation of the 12 Be 2 + 1 state in inelastic proton scattering from 12 Be, consistent with a strong quadrupole deformation.…”

“…In recent years much evidence has been accumulated that 12 Be does not have a good N = 8 neutron closed shell [15][16][17]. Iwasaki et al [15] observed a strong excitation of the 12 Be 2 + 1 state in inelastic proton scattering from 12 Be, consistent with a strong quadrupole deformation. The associated coupled-channels analysis deduced a deformation length δ=2.00±0.23 fm for this state (corresponding to β = 0.728±0.084 when R = 1.2 × A 1/3 ), confirming that the closed shell structure does not prevail in 12 Be.…”

Medium-spin states in neutron-rich83As and81As

“…[1]). Several magic shell gaps are so fragile as several neutron-rich nuclei ( 12 Be 8 , 32 Mg 20 , and 42 Si 28 ) were found to exhibit large collectivity [2][3][4]. As for 78 28 Ni 50 , the two magic numbers, 28 and 50, are created by spin-orbit interaction, such as 6, 14 or 82.…”