Evolution of structure and shapes in 158Er to ultrahigh spin
The level structure of Er158 has been studied using the Gammasphere spectrometer via the Cd114(Ca48,4n) reaction at 215 MeV with both thin (self-supporting) and thick (backed) targets. The level scheme has been considerably extended with more than 200 new transitions and six new rotational structure...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
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American Physical Society
2023
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| _version_ | 1797111587160457216 |
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| author | Simpson, J Riley, MA Pipidis, A Paul, ES Wang, X Nolan, PJ Sharpey-Schafer, JF Aguilar, A Appelbe, DE Ayangeakaa, AD Boston, AJ Boston, HC Campbell, DB Carpenter, MP Chiara, CJ Choy, PTW Clark, RM Cromaz, M Evans, AO Fallon, P Garg, U Gorgen, A Hartley, DJ Janssens, RVF Joss, DT Judson, DS Lauritsen, T Lee, IY Macchiavelli, AO Matta, JT Ollier, J Petri, M Revill, JP Riedinger, LL Rigby, SV Teal, C Twin, PJ Unsworth, C Ward, D Zhu, S Ragnarsson, I |
| author_facet | Simpson, J Riley, MA Pipidis, A Paul, ES Wang, X Nolan, PJ Sharpey-Schafer, JF Aguilar, A Appelbe, DE Ayangeakaa, AD Boston, AJ Boston, HC Campbell, DB Carpenter, MP Chiara, CJ Choy, PTW Clark, RM Cromaz, M Evans, AO Fallon, P Garg, U Gorgen, A Hartley, DJ Janssens, RVF Joss, DT Judson, DS Lauritsen, T Lee, IY Macchiavelli, AO Matta, JT Ollier, J Petri, M Revill, JP Riedinger, LL Rigby, SV Teal, C Twin, PJ Unsworth, C Ward, D Zhu, S Ragnarsson, I |
| author_sort | Simpson, J |
| collection | OXFORD |
| description | The level structure of Er158 has been studied using the Gammasphere spectrometer via the Cd114(Ca48,4n) reaction at 215 MeV with both thin (self-supporting) and thick (backed) targets. The level scheme has been considerably extended with more than 200 new transitions and six new rotational structures, including two strongly coupled high-K bands. Configuration assignments for the new structures are based on their observed alignments, B(M1)/B(E2) ratios of reduced transition probabilities, excitation energies, and comparisons with neighboring nuclei and theoretical calculations. With increasing angular momentum, this nucleus exhibits Coriolis-induced alignments of both neutrons and protons before it then undergoes a rotation-induced transition from near-prolate collective rotation to a noncollective oblate configuration. This transition occurs via the mechanism of band termination around spin 45ħ in three rotational structures. Two distinct lifetime branches, consistent with the crossing of a collective "fast"rotational structure by an energetically favored "slow"terminating sequence, are confirmed for the positive-parity states, and similar behavior is established in the negative-parity states. Weak-intensity, high-energy transitions are observed to feed into the terminating states. At the highest spins, three collective bands with high dynamic moments of inertia and large quadrupole moments were identified. These bands are interpreted as triaxial strongly deformed structures and mark a return to collectivity at ultrahigh spin. |
| first_indexed | 2024-03-07T08:12:30Z |
| format | Journal article |
| id | oxford-uuid:4db3b356-0e8e-46e1-b807-2251295a657d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T08:12:30Z |
| publishDate | 2023 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:4db3b356-0e8e-46e1-b807-2251295a657d2023-12-05T11:15:09ZEvolution of structure and shapes in 158Er to ultrahigh spinJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4db3b356-0e8e-46e1-b807-2251295a657dEnglishSymplectic ElementsAmerican Physical Society2023Simpson, JRiley, MAPipidis, APaul, ESWang, XNolan, PJSharpey-Schafer, JFAguilar, AAppelbe, DEAyangeakaa, ADBoston, AJBoston, HCCampbell, DBCarpenter, MPChiara, CJChoy, PTWClark, RMCromaz, MEvans, AOFallon, PGarg, UGorgen, AHartley, DJJanssens, RVFJoss, DTJudson, DSLauritsen, TLee, IYMacchiavelli, AOMatta, JTOllier, JPetri, MRevill, JPRiedinger, LLRigby, SVTeal, CTwin, PJUnsworth, CWard, DZhu, SRagnarsson, IThe level structure of Er158 has been studied using the Gammasphere spectrometer via the Cd114(Ca48,4n) reaction at 215 MeV with both thin (self-supporting) and thick (backed) targets. The level scheme has been considerably extended with more than 200 new transitions and six new rotational structures, including two strongly coupled high-K bands. Configuration assignments for the new structures are based on their observed alignments, B(M1)/B(E2) ratios of reduced transition probabilities, excitation energies, and comparisons with neighboring nuclei and theoretical calculations. With increasing angular momentum, this nucleus exhibits Coriolis-induced alignments of both neutrons and protons before it then undergoes a rotation-induced transition from near-prolate collective rotation to a noncollective oblate configuration. This transition occurs via the mechanism of band termination around spin 45ħ in three rotational structures. Two distinct lifetime branches, consistent with the crossing of a collective "fast"rotational structure by an energetically favored "slow"terminating sequence, are confirmed for the positive-parity states, and similar behavior is established in the negative-parity states. Weak-intensity, high-energy transitions are observed to feed into the terminating states. At the highest spins, three collective bands with high dynamic moments of inertia and large quadrupole moments were identified. These bands are interpreted as triaxial strongly deformed structures and mark a return to collectivity at ultrahigh spin. |
| spellingShingle | Simpson, J Riley, MA Pipidis, A Paul, ES Wang, X Nolan, PJ Sharpey-Schafer, JF Aguilar, A Appelbe, DE Ayangeakaa, AD Boston, AJ Boston, HC Campbell, DB Carpenter, MP Chiara, CJ Choy, PTW Clark, RM Cromaz, M Evans, AO Fallon, P Garg, U Gorgen, A Hartley, DJ Janssens, RVF Joss, DT Judson, DS Lauritsen, T Lee, IY Macchiavelli, AO Matta, JT Ollier, J Petri, M Revill, JP Riedinger, LL Rigby, SV Teal, C Twin, PJ Unsworth, C Ward, D Zhu, S Ragnarsson, I Evolution of structure and shapes in 158Er to ultrahigh spin |
| title | Evolution of structure and shapes in 158Er to ultrahigh spin |
| title_full | Evolution of structure and shapes in 158Er to ultrahigh spin |
| title_fullStr | Evolution of structure and shapes in 158Er to ultrahigh spin |
| title_full_unstemmed | Evolution of structure and shapes in 158Er to ultrahigh spin |
| title_short | Evolution of structure and shapes in 158Er to ultrahigh spin |
| title_sort | evolution of structure and shapes in 158er to ultrahigh spin |
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