Intermediate-energy Coulomb excitation ofFe52

Abstract

The nucleus 52 Fe with ͑N = Z =26͒ has been investigated using intermediate-energy Coulomb excitation in inverse kinematics. A reduced transition probability of B͑E2;0 1 + → 2 1 + ͒ = 817͑102͒ e 2 fm 4 to the first excited 2 + state at 849.0(5) keV was deduced. The increase in excitation strength B͑E2 ↑ ͒ with respect to the even-mass neighbor 54 Fe (B͑E2 ↑ ͒ = 620͑50͒ e 2 fm 4 ) agrees with shell-model expectations as the magic number N =28 is approached. This measurement completes the systematics of reduced transition strengths to the first excited 2 + state for the even-even N = Z nuclei up to mass A = 56.

One-neutron knockout fromNi57

“…The β-decay of 57 Cu indicated [2] that the Gamov-Teller matrix element of its decay to the ground state of 57 Ni is significantly reduced compared to the single-particle value. Measurements of unusually high collectivity of 56 Ni [3][4][5] reinforced the questions about the single-particle character of the ground and lowest excited states of 57 Ni. The spectroscopic factors for the first three states of 57 Ni were measured in a (d, p) transfer reaction at low energy [6].…”

High-precisionB(E2)measurements of semi-magicNi58,60,62,64Allmond1, Brown2, Stuchbery3 et al. 2014Phys. Rev. CSelf Cite315221View full textAdd to dashboardCite

“…Radioactive 56 Ni and 68 Ni have comparatively large 2 + 1 energies and small B(E2) values [17,18], which alone suggest good N = 28 and N = 40 shell and sub-shell closures, respectively. However, discontinuities in neutron separation energies show weak to no evidence for a N = 40 sub-shell closure for 68 Ni [19,20] [24].…”

Collectivity and instability of theN=Z=28shell gap and strongly deformed bands withg9/2configuration inChiba1, Kimura2 2014Phys. Rev. C4020View full textAdd to dashboardCite

“…Corresponding to these minima, four strongly deformed bands which are classified into three groups of bands 1, 2, and 3 are obtained above E = 20 MeV. Band 1 has prolate shape and has an (f 7 4 . These four bands have smaller moments of inertia than thos of the resonance states observed in Refs.…”

“…The first 2 + state which is one of the spherical levels has a relatively small excitation energy of 2.7 MeV [1] and a relatively large value of B(E2; 2 + → 0 + ) = 112 e 2 fm 4 [2][3][4] compared to other doubly closed-shell nuclei such as 48 Ca, which has the first 2 + state at 3.8 MeV and B(E2; 2 + → 0 + ) = 17 e 2 fm 4 . These observations suggest that 56 Ni is a rather soft double magic nucleus against the collective excitations.…”