Year: 2026
Type: preprint
Abstract: Excited states in $^{148}_{~66}$Dy were populated via $β^+/EC$ decay of $^{148m}$Ho using the GRIFFIN spectrometer at the TRIUMF ISAC-I facility. A combined measurement of the mean lifetime of the $3_1^-$ level using the Generalized Centroid Difference (GCD) method and branching fraction of the $3_1^-\rightarrow0_1^+$ $γ$-ray decay has been performed. From these results, an enhanced electric octupole $B(E3;3_1^-\rightarrow0_1^+)$ transition strength of 46(3)~W.u. has been determined in $^{148}_{~66}$Dy. This is the largest measured value across the closed neutron shell at $N=82$ and provides direct evidence of enhanced octupole collectivity beyond $Z=64$. The evolution of the $B(E3; 3^-_1 \rightarrow 0^+_1)$ strength along the $N=82$ isotonic chain is compared with quasiparticle random-phase approximation (QRPA) calculations using the SkI3 and SkM$^*$ Skyrme energy-density functionals, as well as with large-scale shell-model (SM) calculations. This result extends the boundaries of enhanced octupole collectivity far from the so-called `octupole magic numbers' $Z=56$ and $N=88$.
Source: arXiv (Cornell University)
Authors: Spagnoletti, P., Vedia, V., Yuksel, E., Yu, Y. X., Fu, G. J., Umashankar, R., Andreetta, G., Andreoiu, C., Avaa, A. A., Ball, G. C., Bildstein, V., Buck, S., Cantacuzene, E., Colombi, G., Dillmann, I., Gaffney, L. P., Garnsworthy, A. B., Garrett, P. E., Grinyer, G. F., Hackman, G., Liu, J., Ludlam, A., Luperi, L. L., Madhu, La Marca, T., Movilla-Quintero, D., Morales, S. Murillo, del Alamo, R. Nicolas, Rajabali, M. M., Regan, P. H., Rocchini, M., Scheck, M., Seger, J., Sekal, S., Stramaccioni, D., Svensson, C. E., Tsantiri, A., Williams, J., Wu, F.
Institutions: University of Liverpool, European Organization for Nuclear Research, University of Surrey, Tongji University, TRIUMF, University of British Columbia, University of Padua, Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Simon Fraser University, University of Guelph, University of Regina, University of Victoria, University of the Western Cape, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, CEA Paris-Saclay - Etablissement de Saclay, CEA Paris-Saclay, Institut de Recherche sur les Lois Fondamentales de l'Univers, Consejo Superior de Investigaciones Científicas, Instituto de Estructura de la Materia, Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Tennessee Technological University, National Physical Laboratory, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Helmholtz-Zentrum Hereon
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: U.S. Department of Energy, TRIUMF, National Natural Science Foundation of China, Simon Fraser University, Office of Science, Natural Sciences and Engineering Research Council of Canada, National Research Council Canada, Science and Technology Facilities Council, British Columbia Knowledge Development Fund, European Regional Development Fund, Agencia Estatal de Investigación, Ontario Ministry of Research and Innovation, Nuclear Physics
Awards: G102163711, G1622782223, G1760870335, Nuclear Physics Consolidated Grant 2023, G2110534122, G2287611682, G262962599, G2896472831, G3198348587, G3367111595, G3452655474, G410571670, G451917667, TENSAR - Theory and Experiment for Nuclear Structure, Astrophysics & Reactions, G4911873639, G498139845, G5014604282, G5180915604, G5539308778, G5967599077, G6918803902, G7567680865, G7848167253, G819534099, G877598458, G880751848, G929308097, G935369410, G993149817
OpenAlex ID: W7213869628