Direct lifetime measurements via γ−γ coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N=50) nucleus 94Ru. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in 94Ru were populated primarily via the β-delayed proton emission of 95Pd nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon 124Xe beam impinging on a 4 g/cm29Be target. While the deduced E2 strength for the 2+→0+ transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4+→2+ transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the fpg proton hole space with respect to doubly magic 100Sn. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority ν=2, Iπ=4+ state and that of a close-lying ν=4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6+→4+ transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations.
Description
Phys. Rev. C 105, L031304 (2022) - Nature of seniority symmetry breaking in the semimagic nucleus 94Ru
%0 Journal Article
%1 PhysRevC.105.L031304
%A Das, B.
%A Cederwall, B.
%A Qi, C.
%A Górska, M.
%A Regan, P. H.
%A Aktas, Ö.
%A Albers, H. M.
%A Banerjee, A.
%A Chishti, M. M. R.
%A Gerl, J.
%A Hubbard, N.
%A Jazrawi, S.
%A Jolie, J.
%A Mistry, A. K.
%A Polettini, M.
%A Yaneva, A.
%A Alhomaidhi, S.
%A Zhao, J.
%A Arici, T.
%A Bagchi, S.
%A Benzoni, G.
%A Boutachkov, P.
%A Davinson, T.
%A Dickel, T.
%A Haettner, E.
%A Hall, O.
%A Hornung, Ch.
%A Hucka, J. P.
%A John, P. R.
%A Kojouharov, I.
%A Knöbel, R.
%A Kostyleva, D.
%A Kuzminchuk, N.
%A Mukha, I.
%A Plass, W. R.
%A Nara Singh, B. S.
%A Vasiljevi ́c, J.
%A Pietri, S.
%A Podolyák, Zs.
%A Rudigier, M.
%A Rösch, H.
%A Sahin, E.
%A Schaffner, H.
%A Scheidenberger, C.
%A Schirru, F.
%A Sharma, A.
%A Shearman, R.
%A Tanaka, Y.
%A Vesi ́c, J.
%A Weick, H.
%A Wollersheim, H. J.
%A Ahmed, U.
%A Algora, A.
%A Appleton, C.
%A Benito, J.
%A Blazhev, A.
%A Bracco, A.
%A Bruce, A. M.
%A Brunet, M.
%A Canavan, R.
%A Esmaylzadeh, A.
%A Fraile, L. M.
%A Häfner, G.
%A Heggen, H.
%A Kahl, D.
%A Karayonchev, V.
%A Kern, R.
%A Korgul, A.
%A Kosir, G.
%A Kurz, N.
%A Lozeva, R.
%A Mikolajczuk, M.
%A Napiralla, P.
%A Page, R.
%A Petrache, C. M.
%A Pietralla, N.
%A Régis, J.-M.
%A Ruotsalainen, P.
%A Sexton, L.
%A Sanchez-Temble, V.
%A Si, M.
%A Vilhena, J.
%A Werner, V.
%A Wiederhold, J.
%A Witt, W.
%A Woods, P. J.
%A Zimba, G.
%D 2022
%I American Physical Society
%J Phys. Rev. C
%K jolie myown
%N 3
%P L031304
%R 10.1103/PhysRevC.105.L031304
%T Nature of seniority symmetry breaking in the semimagic nucleus 94Ru
%U https://link.aps.org/doi/10.1103/PhysRevC.105.L031304
%V 105
%X Direct lifetime measurements via γ−γ coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N=50) nucleus 94Ru. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in 94Ru were populated primarily via the β-delayed proton emission of 95Pd nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon 124Xe beam impinging on a 4 g/cm29Be target. While the deduced E2 strength for the 2+→0+ transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4+→2+ transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the fpg proton hole space with respect to doubly magic 100Sn. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority ν=2, Iπ=4+ state and that of a close-lying ν=4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6+→4+ transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations.
@article{PhysRevC.105.L031304,
abstract = {Direct lifetime measurements via γ−γ coincidences using a fast timing detector array consisting of LaBr3(Ce) scintillators has been applied to determine the lifetime of low-lying states in the semimagic (N=50) nucleus 94Ru. The experiment was carried out as the first in a series of “FAIR-0” experiments with the DESPEC experimental setup at the Facility for Antiproton and Ion Research (FAIR). Excited states in 94Ru were populated primarily via the β-delayed proton emission of 95Pd nuclei, produced in the projectile fragmentation of an 850 MeV/nucleon 124Xe beam impinging on a 4 g/cm29Be target. While the deduced E2 strength for the 2+→0+ transition in the yrast cascade follows the expected behavior for conserved seniority symmetry, the intermediate 4+→2+ transition exhibits a drastic enhancement of transition strength in comparison with pure-seniority model predictions as well as standard shell model predictions in the fpg proton hole space with respect to doubly magic 100Sn. The anomalous behavior is ascribed to a subtle interference between the wave function of the lowest seniority ν=2, Iπ=4+ state and that of a close-lying ν=4 state that exhibits partial dynamic symmetry. In addition, the observed strongly prohibitive 6+→4+ transition can be attributed to the same mechanism but with a destructive interference. It is noted that such effects may provide stringent tests of the nucleon-nucleon interactions employed in state-of-the-art theoretical model calculations.},
added-at = {2023-04-14T13:03:34.000+0200},
author = {Das, B. and Cederwall, B. and Qi, C. and Górska, M. and Regan, P. H. and Aktas, Ö. and Albers, H. M. and Banerjee, A. and Chishti, M. M. R. and Gerl, J. and Hubbard, N. and Jazrawi, S. and Jolie, J. and Mistry, A. K. and Polettini, M. and Yaneva, A. and Alhomaidhi, S. and Zhao, J. and Arici, T. and Bagchi, S. and Benzoni, G. and Boutachkov, P. and Davinson, T. and Dickel, T. and Haettner, E. and Hall, O. and Hornung, Ch. and Hucka, J. P. and John, P. R. and Kojouharov, I. and Knöbel, R. and Kostyleva, D. and Kuzminchuk, N. and Mukha, I. and Plass, W. R. and Nara Singh, B. S. and Vasiljevi ́c, J. and Pietri, S. and Podolyák, Zs. and Rudigier, M. and Rösch, H. and Sahin, E. and Schaffner, H. and Scheidenberger, C. and Schirru, F. and Sharma, A. and Shearman, R. and Tanaka, Y. and Vesi ́c, J. and Weick, H. and Wollersheim, H. J. and Ahmed, U. and Algora, A. and Appleton, C. and Benito, J. and Blazhev, A. and Bracco, A. and Bruce, A. M. and Brunet, M. and Canavan, R. and Esmaylzadeh, A. and Fraile, L. M. and Häfner, G. and Heggen, H. and Kahl, D. and Karayonchev, V. and Kern, R. and Korgul, A. and Kosir, G. and Kurz, N. and Lozeva, R. and Mikolajczuk, M. and Napiralla, P. and Page, R. and Petrache, C. M. and Pietralla, N. and Régis, J.-M. and Ruotsalainen, P. and Sexton, L. and Sanchez-Temble, V. and Si, M. and Vilhena, J. and Werner, V. and Wiederhold, J. and Witt, W. and Woods, P. J. and Zimba, G.},
biburl = {https://www.bibsonomy.org/bibtex/2ab2438361097b6946b476dc08d67944a/ikpcologne},
description = {Phys. Rev. C 105, L031304 (2022) - Nature of seniority symmetry breaking in the semimagic nucleus 94Ru},
doi = {10.1103/PhysRevC.105.L031304},
interhash = {a45c31ae556852153dc6f1f22d4061d0},
intrahash = {ab2438361097b6946b476dc08d67944a},
journal = {Phys. Rev. C},
keywords = {jolie myown},
month = mar,
number = 3,
numpages = {6},
pages = {L031304},
publisher = {American Physical Society},
timestamp = {2023-04-14T13:03:34.000+0200},
title = {Nature of seniority symmetry breaking in the semimagic nucleus 94Ru},
url = {https://link.aps.org/doi/10.1103/PhysRevC.105.L031304},
volume = 105,
year = 2022
}