Spectroscopic calculations of cluster nuclei above double shell closures with a new local potential

Abstract

Using a new local cluster potential, cluster structures around double shell closures have been investigated. The calculations of spectra including electromagnetic transitions are in reasonable agreement with experimental data. Besides the nuclei, 20 Ne, 44 Ti, 60 Zn, and 212 Po, which have been intensively analyzed by cluster models, we have also studied two other good candidates, 52 Ti and 136 Te, for α-cluster structure in neutron-rich regions. In 136 Te, the unexpectedly small B(E2; 0 + → 2 + ) would be due to the cluster characteristic. The new cluster potential without any readjustment of the parameter values has been also applied to the investigations of possible 6 He-cluster structure in nuclei, 22 Ne, 46 Ti, 54 Ti, 62 Zn, and 138 Te, which have the same doubly magic cores as the α-cluster nuclei above. Similarly good results can be obtained, compared with experimental data. It is an advantage that the new cluster potential suits the different types of cluster structures with a set of fixed parameters which do not need any readjustment for different cluster-core structures.

Spectroscopy and lifetime measurements in Te134,136,138 isotopes and implications for the nuclear structure beyond N=82Häfner1, Lozeva2, Naïdja3 et al. 2021Phys. Rev. C103180View full textAdd to dashboardCite

“…Also, our quadrupole moment Q(2 + 1 ) = −33 e fm 2 value agrees very well with their measurement [−45(23) e fm 2 ] [9], and that of their SM1 (−30 e fm 2 ), reported in the same reference. We also compare our results with several other types of shell-model calculations using different interactions and set of effective charges in Table III such as NSM [57], MCSM [1], as well as QRPA [3,58] and α-cluster model [59,60]. The experimental margin is well covered with the various theoretical results especially for A = 136.…”

Cluster-daughter overlap as a new probe of alpha-cluster formation in medium-mass and heavy even–even nuclei

“…Alpha-cluster formation could also exist in the medium-mass nuclei. Possible candidates include 46,54 Cr = α + 42,50 Ti [38,39], 90 Sr = α + 86 Kr [40], 92 Zr = α + 88 Sr [40], 94 Mo = α + 90 Zr [40][41][42][43], 96 Ru = α + 92 Mo [40], 98 Pd = α + 94 Ru [40], 136 Te = α + 132 Sn [44], etc. Recently, there are also systematic studies on the landscape of alpha-cluster formation probabilities in medium-mass nuclei using alpha-decay data [45].…”

“…This idea is then explored in detail by generations of nuclear physicists, and inspires many important theoretical developments, such as resonating group method [9], generator coordinate method [10], antisymmetrized molecular dynamics [12], orthogonality condition method [11], THSR (Tohsaki-Horiuchi-Schuck-Röpke) wave function [13], etc. It is found that there could be alpha-cluster structures in ground states of light nuclei such as 8 Be = α + α, 20 Ne = α + 16 O, 44 Ti = α + 40 Ca [4], as well as in the famous Hoyle and Hoyle-like excited states of self-conjugate nuclei near alpha-particle disintegration thresholds [13][14][15][16][17]. The study of alpha-cluster formation in heavy/superheavy nuclei could date back to Rutherford's discovery of alpha decay more than one hundred years ago [18].…”

First-excited state g factor of Te136 by the recoil in vacuum method

“…The excitation energies, transition rates, and static moments are sensitive to shell structure, the strength of the proton-neutron interactions, and to developing collectivity [1][2][3][4][5][6][7][8][9][10]. Following the observation of an anomalously low B(E2; 0 + 1 → 2 + 1 ) by Radford et al [11], the case of 136 Te, with two protons and two neutrons outside the 132 Sn core, has been the subject of many theoretical studies, with widely varying predictions of the electromagnetic properties of the low-excitation states [1-5, 9, 10].…”