Cluster Thomas-Ehrman effect in mirror nuclei

Enhanced monopole and dipole transitions in nuclei induced by α cluster structures

“…Theoretical calculation is 1.1 in a unit of the single particle strength, and this result nicely reproduces the observed strength [11]. 18 O with the E0 strength [11].…”

“…The 0 + 2 state appears at the low excitation energy of E x ∼ 4 MeV but the observed E0 strength to this state is 1.5 times larger than the strength for the single particle excitation [16]. Theoretical calculation is 1.1 in a unit of the single particle strength, and this result nicely reproduces the observed strength [11]. 18 O with the E0 strength [11].…”

“…As for 12 Be, we assume the six-body systems of α + α + 4N and employ the generalized two-center cluster model (GTCM) [10], which is possible to handle the atomic structure with the binary He-clusters and the covalent structure of excess four neutrons around two α cores. On the contrary, the orthogonality condition model (OCM) with the α + 14 C cluster configuration is used for the structure calculation of 18 O [11]. Both calculations nicely reproduce the level sequence of the 0 + states.…”

“…In this report, we show our analyses for the light nuclei, such as 12 Be [10] and 18 O [11], which are based on the microscopic and semi-microscrpic α cluster models, and point out that the strong monopole transition is induced by the α cluster excitation. Furthermore, we analyze the monopole and dipole transitions in the heavier systems, 44 Ti and 104−110 Te, by applying the macroscopic α cluster model, which is based on the double folding potential of the α particle and residual core nuclei.…”

Coulomb Shift in Two-Center Cluster Systems

“…If TES occurs in the α cluster states, we will observe the compressed excitation energy of the excited 0 + states in the proton-rich system. In fact, such the compression of the excitation energy for the excited 0 + states has been briefly discussed in 10 Be − 10 C from the viewpoint of the covalent molecular picture [3].…”