Coulomb Excitation of $^{80}$Sr and the limits of the $N = Z = 40$ island of deformation

Autor: Russell, R., Heery, J., Henderson, J., Wadsworth, R., Kaneko, K., Shimizu, N., Mizusaki, T., Sun, Y., Andreoiu, C., Annen, D. W., Avaa, A. A., Ball, G. C., Bildstein, V., Buck, S., Cousins, C., Garnsworthy, A. B., Gillespie, S. A., Greaves, B., Grimes, A., Hackman, G., Hughes, R. O., Jenkins, D. G., Kowalewski, T. M., Martin, M. S., Müller-Gatermann, C., Murias, J. R., Murillo-Morales, S., Pascu, S., Rhodes, D. M., Smallcombe, J., Spagnoletti, P., Svensson, C. E., Wallis, B., Williams, J., Wu, C. Y., Yates, D.
Rok vydání: 2024
Předmět:
Druh dokumentu: Working Paper
Popis: The region of $N\approx Z\approx 40$ has long been associated with strongly deformed nuclear configurations. The presence of this strong deformation was recently confirmed through lifetime measurements in $N\approx Z$ Sr and Zr nuclei. Theoretically, however, these nuclei present a challenge due to the vast valence space required to incorporate all deformation driving interactions. Recent state-of-the-art predictions indicate a near axial prolate deformation for $N=Z$ and $N=Z+2$ nuclei between $N=Z=36$ and $N=Z=40$. In this work we investigate the shores of this island of deformation through a sub-barrier Coulomb excitation study of the $N=Z+4$ nucleus, \textsuperscript{80}Sr. Extracting a spectroscopic quadrupole moment of $Q_s(2^+_1) = 0.45^{+0.83}_{-0.88}$~eb, we find that \textsuperscript{80}Sr is inconsistent with significant axial prolate deformation. This indicates that the predicted region of strong prolate deformation around $N=Z=40$ is tightly constrained to the quartet of nuclei: \textsuperscript{76,78}Sr and \textsuperscript{78,80}Zr.
Comment: Submitted to Physics Letters B
Databáze: arXiv