Abstract.
The excited states of 169Tm have been studied via the 169Tm(32S,32S′)169Tm* reaction at the beam energy of 164MeV. The \(\gamma\)-rays were detected using the Indian National Gamma Array (INGA) setup, composed of 19 Compton-suppressed clover HPGe detectors. A new level scheme of 169Tm with 11 newly placed \( \gamma\)-rays has been proposed. A band crossing in the \( \pi [541]1/2^{-}\) band and several interband E1 transitions between this and the \( \pi [411]1/2^{+}\) ground-state band have been observed for the first time in this nucleus. The role of the \(N=98\) deformed shell gap has been discussed by comparing the band crossing parameters of the negative parity bands in Tm and other neighboring nuclei. The origin of the interband E1 transitions has been investigated in terms of coupling to octupole degrees of freedom. The shape evolution of the Tm isotopes around \( N=98\) have been studied in the projected and cranked shell model approaches, both of which predict a change in shape from an axial prolate to a triaxial one after band crossing in these nuclei. The new data and the calculations help to understand the unusual structural phenomena reported for the nuclei with \( N=98\).
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
H.J. Jensen et al., Nucl. Phys. A 695, 3 (2001)
M.J. Burns et al., J. Phys. G: Nucl. Part. Phys. 31, S1827 (2005)
S. Olbrich et al., Nucl. Phys. A 342, 133 (1980)
H.J. Jensen et al., Z. Phys. A 359, 127 (1997)
D. Barnëoud, C. Foin, S. Andrë, H. Abou-Leila, S.A. Hjorth, Nucl. Phys. A 230, 445 (1974)
M.P. Robinson et al., Nucl. Phys. A 647, 175 (1999)
S. Drissi et al., Nucl. Phys. A 483, 153 (1988)
X. Wang et al., Phys. Rev. C 75, 064315 (2007)
D.J. Hartley et al., Phys. Rev. Lett. 120, 182502 (2018)
P. Taras et al., Nucl. Phys. A 289, 165 (1977)
Carlos E. Vargas, Jorge G. Hirsch, Jerry P. Draayer, Phys. Rev. C 66, 064309 (2002)
Md.A. Asgar et al., Phys. Rev. C 95, 031304(R) (2017)
K. Starosta et al., Nucl. Instrum. Methods Phys. Res. A 423, 16 (1999)
Ch. Droste et al., Nucl. Instrum. Methods Phys. Res. A 378, 518 (1996)
E.S. Macias et al., Comput. Phys. Commun. 11, 75 (1976)
S. Nandi et al., Phys. Rev. C 99, 054312 (2019)
R. Palit et al., Pramana J. Phys. 54, 347 (2000)
M.A. Jones et al., Nucl. Phys. A 605, 133 (1996)
S.J. Zhu et al., Phys. Lett. B 357, 273 (1995)
W. Urban et al., Phys. Rev. C 54, 945 (1996)
S.J. Zhu et al., Phys. Rev. C 59, 1316 (1999)
Y.J. Chen et al., Phys. Rev. C 73, 054316 (2006)
Somapriya Basu et al., Phys. Rev. C 49, 650 (1994)
M. Riley et al., Phys. Rev. C 51, 1234 (1995)
W. Nazarewicz, P. Olanders, Nucl. Phys. A 441, 420 (1985)
K. Hara, Y. Sun, Nucl. Phys. A 529, 445 (1991)
Y. Sun et al., Phys. Rev. C 80, 054306 (2009)
P. Ring, P. Schuck, The Nuclear Many-Body Problem, 1st edition (Springer-Verlag Berlin Heidelberg, 1980)
K. Hara, Y. Sun, Int. J. Mod. Phys. E 4, 637 (1995)
P. Möller, J.R. Nix, W.D. Myers, W.J. Swiatecki, At. Data Nucl. Data Tables 59, 185 (1995)
T. Roy et al., Phys. Lett. B 782, 768 (2018)
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by C. Ur
Data Availability Statement
This manuscript has no associated data or the data will not be deposited. [Authors’ comment: All data generated during this study are contained in this published article.]
Publisher’s Note
The EPJ Publishers remain neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Asgar, M.A., Mukherjee, G., Roy, T. et al. Band structures in 169Tm and the structures of Tm isotopes around N = 98. Eur. Phys. J. A 55, 175 (2019). https://doi.org/10.1140/epja/i2019-12882-3
Received:
Accepted:
Published:
DOI: https://doi.org/10.1140/epja/i2019-12882-3