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12 results on '"Auranen, K."'

1. First observation of high-$K$ isomeric states in $^{249}$Md and $^{251}$Md

Author

Goigoux, T., Theisen, Ch., Sulignano, B., Airiau, M., Auranen, K., Badran, H., Briselet, R., Calverley, T., Cox, D., Déchery, F., Bisso, F. Defranchi, Drouart, A., Favier, Z., Gall, B., Grahn, T., Greenlees, P. T., Hauschild, K., Herzáň, A., Herzberg, R. -D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lightfoot, A., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Partanen, J., Peura, P., Rahkila, P., Rey-Herme, E., Rubert, J., Ruotsalainen, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Vandebrouck, M., Ward, A., Zielińska, M., Jachimowicz, P., Kowal, M., and Skalski, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Decay spectroscopy of the odd-proton nuclei $^{249}$Md and $^{251}$Md has been performed. High-$K$ isomeric states were identified for the first time in these two nuclei through the measurement of their electromagnetic decay. An isomeric state with a half-life of $2.8(5)$ ms and an excitation energy $\geq 910$ keV was found in $^{249}$Md. In $^{251}$Md, an isomeric state with a half-life of $1.4(3)$ s and an excitation energy $\geq 844$ keV was found. Similarly to the neighbouring $^{255}$Lr, these two isomeric states are interpreted as 3 quasi-particle high-$K$ states and compared to new theoretical calculations. Excited nuclear configurations were calculated within two scenarios: via blocking nuclear states located in proximity to the Fermi surface or/and using the quasiparticle Bardeen-Cooper-Schrieffer method. Relevant states were selected on the basis of the microscopic-macroscopic model with a deformed Woods-Saxon potential. The most probable candidates for the configurations of $K$-isomeric states in Md nuclei are proposed.

Published
2021
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2. Shape Coexistence at Zero Spin in 64Ni Driven by the Monopole Tensor Interaction

Author

Mărginean, N., Little, D., Tsunoda, Y., Leoni, S., Janssens, R. V. F., Fornal, B., Otsuka, T., Michelagnoli, C., Stan, L., Crespi, F. C. L., Costache, C., Lica, R., Sferrazza, M., Turturica, A., Ayangeakaa, A. D., Auranen, K., Barani, M., Bender, P. C., Bottoni, S., Boromiza, M., Bracco, A., Călinescu, S., Campbell, C. M., Carpenter, M. P., Chowdhury, P., Ciemała, M., Cieplicka-Orynczak, N., Cline, D., Clisu, C., Crawford, H. L., Dinescu, I. E., Filipescu, D., Florea, N., Forney, A. M., Fracassetti, S., Gade, A., Gheorghe, I., Hayes, A. B., Harca, I., Henderson, J., Ionescu, A., Iskra, Ł. W., Jentschel, M., Kandzia, F., Kim, Y. H., Kondev, F. G., Korschinek, G., Köster, U., Krishichayan, Krzysiek, M., Lauritsen, T., Li, J., Mărginean, R., Maugeri, E. A., Mihai, C., Mihai, R. E., Mitu, A., Mutti, P., Negret, A., Niţă, C. R., Olăcel, A., Oprea, A., Pascu, S., Petrone, C., Porzio, C., Rhodes, D., Seweryniak, D., Schumann, D., Sotty, C., Stolze, S. M., Şuvăilă, R., Toma, S., Ujeniuc, S., Walters, W. B., Wu, C. Y., Wu, J., Zhu, S., and Ziliani, S.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The low-spin structure of the semimagic 64Ni nucleus has been considerably expanded: combining four experiments, several 0+ and 2+ excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0+ excitation is located at a surprisingly high energy (3463 keV), with a collective 2+ state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N = 40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

Published
2020
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3. In-beam gamma-ray and electron spectroscopy of $^{249,251}$Md

Author

Briselet, R., Theisen, Ch., Sulignano, B., Airiau, M., Auranen, K., Cox, D. M., Déchery, F., Drouart, A., Favier, Z., Gall, B., Goigoux, T., Grahn, T., Greenlees, P. T., Hauschild, K., Herzan, A., Herzberg, R. -D., Jakobsson, U., Julin, R., Juutinen, S., Konki, J., Leino, M., Lopez-Martens, A., Mistry, A., Nieminen, P., Pakarinen, J., Papadakis, P., Peura, P., Rahkila, P., Rey-Herme, E., Rubert, J., Ruotsalainen, P., Sandzelius, M., Sarén, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Vandebrouck, M., Ward, A., Zielińska, M., Bally, B., Bender, M., and Ryssens, W.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The odd-$Z$ $^{251}$Md nucleus was studied using combined $\gamma$-ray and conversion-electron in-beam spectroscopy. Besides the previously observed rotational band based on the $[521]1/2^-$ configuration, another rotational structure has been identified using $\gamma$-$\gamma$ coincidences. The use of electron spectroscopy allowed the rotational bands to be observed over a larger rotational frequency range. Using the transition intensities that depend on the gyromagnetic factor, a $[514]7/2^-$ single-particle configuration has been inferred for this band, i.e., the ground-state band. A physical background that dominates the electron spectrum with an intensity of $\simeq$ 60% was well reproduced by simulating a set of unresolved excited bands. Moreover, a detailed analysis of the intensity profile as a function of the angular momentum provided a method for deriving the orbital gyromagnetic factor, namely $g_K = 0.69^{+0.19}_{-0.16}$ for the ground-state band. The odd-$Z$ $^{249}$Md was studied using $\gamma$-ray in-beam spectroscopy. Evidence for octupole correlations resulting from the mixing of the $\Delta l = \Delta j = 3$ $[521]3/2^-$ and $[633]7/2^+$ Nilsson orbitals were found in both $^{249,251}$Md. A surprising similarity of the $^{251}$Md ground-state band transition energies with those of the excited band of $^{255}$Lr has been discussed in terms of identical bands. Skyrme-Hartree-Fock-Bogoliubov calculations were performed to investigate the origin of the similarities between these bands.

Published
2020
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4. Evidence for rigid triaxial deformation in $^{76}$Ge from a model-independent analysis

Author

Ayangeakaa, A. D., Janssens, R. V. F., Zhu, S., Little, D., Henderson, J., Wu, C. Y., Hartley, D. J., Albers, M., Auranen, K., Bucher, B., Carpenter, M. P., Chowdhury, P., Cline, D., Crawford, H. L., Fallon, P., Forney, A. M., Gade, A., Hayes, A. B., Kondev, F. G., Krishichayan, Lauritsen, T., Li, J., Macchiavelli, A. O., Rhodes, D., Seweryniak, D., Stolze, S. M., Walters, W. B., and Wu, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

An extensive, model-independent analysis of the nature of triaxial deformation in $^{76}$Ge, a candidate for neutrinoless double-beta ($0\nu\beta\beta$) decay, was carried out following multi-step Coulomb excitation. Shape parameters deduced on the basis of a rotational-invariant sum-rule analysis provided considerable insight into the underlying collectivity of the ground-state and $\gamma$ bands. Both sequences were determined to be characterized by the same $\beta$ and $\gamma$ deformation parameter values. In addition, compelling evidence for low-spin, rigid triaxial deformation in $^{76}$Ge was obtained for the first time from the analysis of the statistical fluctuations of the quadrupole asymmetry deduced from the measured $E2$ matrix elements. These newly determined shape parameters are important input and constraints for calculations aimed at providing, with suitable accuracy, the nuclear matrix elements relevant to $0\nu\beta\beta$., Comment: 6 pages, 5 figures

Published
2019
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5. In-beam spectroscopic study of $^{244}$Cf

Author

Konki, J., Sulignano, B., Greenlees, P. T., Theisen, Ch., Auranen, K., Badran, H., Briselet, R., Cox, D. M., Bisso, F. Defranchi, Dobaczewski, Jacek Jan, Grahn, T., Herzan, A., Herzberg, R.-D., Julin, R., Juutinen, S., Khuyagbaatar, J., Leino, M., Lightfoot, A., Pakarinen, J., Papadakis, P., Partanen, J., Rahkila, P., Sandzelius, M., Saren, J., Scholey, C., Shi, Y., Smolen, M., Sorri, J., Stolze, S., Uusitalo, J., Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
level densities, alpha decay, electromagnetic transitions, Nuclear Theory, lifetimes, widths, ddc:530, energy levels, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], ydinfysiikka, Nuclear Experiment
Abstract

The ground-state rotational band of the neutron-deficient californium ( Z = 98 ) isotope 244 Cf was identified for the first time and measured up to a tentative spin and parity of I π = 20 + . The observation of the rotational band indicates that the nucleus is deformed. The kinematic and dynamic moments of inertia were deduced from the measured γ -ray transition energies. The behavior of the dynamic moment of inertia revealed an up-bend due to a possible alignment of coupled nucleons in high- j orbitals starting at a rotational frequency of about ℏ ω = 0.20 MeV . The results were compared with the systematic behavior of the even-even N = 146 isotones as well as with available theoretical calculations that have been performed for nuclei in the region. peerReviewed

Published
2018

6. Spin-dependent evolution of collectivity in 112Te

Author

Doncel, M., Back, T., Qi, C., Cullen, David, Hodge, Duncan, Cederwall, B., Procter, Mark, Auranen, K., Grahn, T., Greenlees, P.T., Jakobsson, U., Julin, R., Juutinen, S., Herzan, A., Konki, J., Pakarinen, J., Partanen, J., Peura, P., Rahkila, P., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Sorri, J., Stolze, S., and Uusitalo, J.

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

The evolution of collectivity with spin along the yrast line in the neutron-deficient nucleus 112Te has been studied by measuring the reduced transition probability of excited states in the yrast band. In particular, the lifetimes of the 4+ and 6+ excited states have been determined by using the recoil distance Doppler-shift method. The results are discussed using both large-scale shell-model and total Routhian surface calculations.

Published
2017

7. Lifetime measurements of excited states in $^{162}$W and $^{164}$W and the evolution of collectivity in rare-earth nuclei

Author

Doncel, M., Cederwall, B., Qi, C., Li, H., Jakobsson, U., Auranen, K., Bönig, S., Drummond, M.C., Grahn, T., Greenlees, P.T., Herzan, A., Joss, D.T., Julin, R., Juutinen, S., Konki, J., Kröll, T., Leino, M., McPeake, C., O'Donnell, D., Page, R.D., Pakarinen, J., Partanen, J., Peura, P., Rahkila, P., Ruotsalainen, P., Sandzelius, M., Sarén, J., Sayğı, B., Scholey, C., Sorri, J., Stolze, S., Taylor, M.J., Thornthwaite, A., Uusitalo, J., Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
Nuclear Theory, lifetimes, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear Experiment, rare-earth nuclei, excited states
Abstract

International audience; Lifetimes of the first excited 2+ states in the extremely neutron-deficient $^{162}$W and $^{164}$W nuclei have been measured using the recoil distance Doppler shift technique. Experimental B(E2) data for the isotopic chains of hafnium, tungsten, and osmium, from the midshell region near the β-stability line towards the N=82 closed shell and the most neutron-deficient nuclides, are compared with predictions of nuclear deformations and 21+→0g.s.+ reduced transition strengths from different classes of state-of-the-art theoretical model calculations. The results reveal striking differences and deficiencies in the predictive power of current nuclear structure models.

Published
2017

8. De-excitation of the strongly coupled band in 177Au and implications for core intruder configurations in the light Hg isotopes

Author

Venhart, M., Ali, F. A., Ryssens, W., Wood, J. L., Joss, D. T., Andreyev, A. N., Auranen, K., Bally, B., Balogh, M., Bender, M., Carroll, R. J., Easton, J. L., Greenlees, P. T., Grahn, T., Heenen, P.-H., Herzáifmmode ecknelse n, A., Jakobsson, U., Julin, R., Juutinen, S., Kifmmode lelse ifmmode eckcelse c, D., Konki, J., Lawrie, E., Leino, M., Matouifmmode eckselse sek, V., McPeake, C. G., O'Donnell, D., Page, R. D., Pakarinen, J., Partanen, J., Peura, P., Rahkila, P., Ruotsalainen, P., Sandzelius, M., Sarén, J., B., Sayifmmode gelse, Sedlák, M., Scholey, C., Sorri, J., Stolze, S., Thornthwaite, A., Uusitalo, J., Veselský, M., Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
atomit, nuklidit, Nuclear Theory, strongly coupled band, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], core intruder configurations, Nuclear Experiment, ydinfysiikka
Abstract

International audience; Excited states in the proton-unbound nuclide $^{177}$Au were populated in the $^92}$Mo($^{88}$Sr, p2n) reaction and identified using the Jurogam-II and GREAT spectrometers in conjunction with the RITU gas-filled separator at the University of Jyväskylä Accelerator Laboratory. A strongly coupled band and its decay path to the 11/2−α-decaying isomer have been identified using recoil-decay tagging. Comparisons with cranked Hartree-Fock-Bogoliubov (HFB) calculations based on Skyrme energy functionals suggest that the band has a prolate deformation and is based upon coupling the odd 1h11/2 proton hole to the excited 02+ configuration in the $^{178}$Hg core. Although these configurations might be expected to follow the parabolic trend of core Hg(02+) states as a function of neutron number, the electromagnetic decay paths from the strongly coupled band in $^{177}$Au are markedly different from those observed in the heavier isotopes above the midshell. This indicates that a significant change in the structure of the underlying A+1Hg core occurs below the neutron midshell.

Published
2017

9. Collective 2(1)(+) excitations in Po-206 and Rn-208,Rn-210

Author

Grahn, T, Pakarinen, J, Jokiniemi, L, Albers, M, Auranen, K, Bauer, C, Bernards, C, Blazhev, A, Butler, PA, Boenig, S, Damyanova, A, De Coster, T, De Witte, H, Elseviers, J, Gaffney, LP, Huyse, M, Herzan, A, Jakobsson, U, Julin, R, Kesteloot, N, Konki, J, Kroell, Th, Lewandowski, L, Moschner, K, Peura, P, Pfeiffer, M, Radeck, D, Rahkila, P, Rapisarda, E, Reiter, P, Reynders, K, Rudiger, M, Salsac, M-D, Sambi, S, Scheck, M, Seidlitz, M, Siebeck, B, Steinbach, T, Stolze, S, Suhonen, J, Thoele, P, Thuerauf, M, Warr, N, Van Duppen, P, Venhart, M, Vermeulen, MJ, Werner, V, Veselsky, M, Vogt, A, Wrzosek-Lipska, K, and Zielinska, M

Subjects
Nuclear Theory, Physics::Accelerator Physics, Nuclear Experiment
Abstract

In the present study, values have been measured in the 208,210Rn and 206Po nuclei through Coulomb excitation of re-accelerated radioactive beams in inverse kinematics at CERN-ISOLDE. These nuclei have been proposed to lie in, or at the boundary of the region where the seniority scheme should persist. However, contributions from collective excitations are likely to be present when moving away from the N=126 closed shell. Such an effect is confirmed by the observed increased collectivity of the transitions. Experimental results have been interpreted with the aid of theoretical studies carried out within the BCS-based QRPA framework. ispartof: European Physical Journal A, Hadrons and Nuclei vol:52 issue:11 status: published

Published
2016

10. Identification of the J = 1− state in 218Ra populated via decay of 222Th

Author

Parr, Edward, Smith, J.F., Greenlees, P.T., Smolen, M., Papadakis, P., Auranen, K., Chapman, R, Cullen, David, Grahn, T, Grocutt, L., Herzberg, R-D, Hodge, D, Jakobsson, U, Julin, R., Juutinen, S, Konki, J, Leino, M, McPeake, C. G., Mengoni, D., Mistry, A, Mulholland, K. F., O'Neill, G.G., Pakarinen, J, Partanen, J., Peura, P, Rahkila, P., Ruotsalainen, P, Sandzelius, M., Saren, J., Scheck, M, Scholey, C., Sorri, J., Stolze, S., Taylor, Michael J, and Uusitalo, J.

Subjects
Nuclear Theory
Abstract

The α decay of Th222 populating the low-lying Jπ=3− state, and also a proposed 1− state, in Ra218 has been observed. The observations suggest an excitation energy of 853 keV for the 1− state, which is 60 keV above the 3− state. The hindrance factors of these α decays give a possible boundary to the region of ground-state octupole deformation in the light-actinide nuclei. The relative positions of the Jπ=1− and 3− states suggest they are produced by an octupole-vibrational mechanism, as opposed to α clustering or rotations of a reflection-asymmetric octupole-deformed shape.

Published
2016

11. Identification of the J(pi)=1(-) state in Ra-218 populated via alpha decay of Th-222

Author

Parr, E, Smith, JF, Greenlees, PT, Smolen, M, Papadakis, P, Auranen, K, Chapman, R, Cullen, DM, Grahn, T, Grocutt, L, Herzan, A, Herzberg, R-D, Hodge, D, Jakobsson, U, Julin, R, Juutinen, S, Konki, J, Leino, M, McPeake, C, Mengoni, D, Mistry, AK, Mulholland, KF, O'Neill, GG, Pakarinen, J, Partanen, J, Peura, P, Rahkila, P, Ruotsalainen, P, Sandzelius, M, Saren, J, Scheck, M, Scholey, C, Sorri, J, Stolze, S, Taylor, MJ, and Uusitalo, J

Subjects
Nuclear Theory, Physical Sciences, Fysik
Abstract

The alpha decay of Th-222 populating the low-lying J(pi) = 3(-) state, and also a proposed 1(-) state, in Ra-218 has been observed. The observations suggest an excitation energy of 853 keV for the 1(-) state, which is 60 keV above the 3(-) state. The hindrance factors of these alpha decays give a possible boundary to the region of ground-state octupole deformation in the light-actinide nuclei. The relative positions of the J(pi) = 1(-) and 3(-) states suggest they are produced by an octupole-vibrational mechanism, as opposed to alpha clustering or rotations of a reflection-asymmetric octupole-deformed shape. QC 20160819

Published
2016

12. Oblately deformed isomeric proton-emitting state in Lu-151

Author

Taylor, M.J., Cullen, D.M., Procter, M.G., Smith, A.J., McFarlane, A., Twist, V., Alharshan, G.A., Ferreira, L.S., Maglione, E., Auranen, K., Grahn, T., Greenlees, P.T., Hauschild, K., Herzan, A., Jakobsson, U., Julin, R., Juutinen, S., Ketelhut, S., Konki, J., Leino, M., Lopez-Martens, A., Pakarinen, J., Partanen, J., Peura, P., Rahkila, P., Rinta-Antila, S., Ruotsalainen, P., Sandzelius, M., Saren, J., Scholey, C., Sorri, J., Stolze, S., Uusitalo, J., Doncel, M., CSNSM SNO, Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)-Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
[PHYS]Physics [physics], NUCLEI, Physical Sciences, Nuclear Theory, TOTAL DATA READOUT, Fysik, Physics::Accelerator Physics, DRIP-LINE, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], DECAY, GAMMA-RAY SPECTROSCOPY
Abstract

International audience; Gamma rays from excited states feeding a proton-emitting isomeric-state in Lu-151 have been observed for the first time. Comparison with state-of-the-art nonadiabatic quasiparticle calculations indicates an oblately deformed, 3/2(+) proton-emitting state with a quadrupole deformation of beta(2) = -0.11. The calculations suggest an increase in quadrupole deformation, to beta(2) = -0.18, with increasing spin which is understood in terms of the mixing of Nilsson states at the Fermi surface. It is also shown that the proton decay half-life is consistent with that from a 3/2(+) state with a quadrupole deformation of beta(2) = -0.12.

Published
2015

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