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Title: Damping mechanisms of high-lying single-particle states in {sup 91}Nb

Abstract

Decay by proton emission from high-lying states in {sup 91}Nb, populated in the {sup 90}Zr({alpha},t) reaction at E{sub {alpha}}=180 MeV, has been investigated. Decay to the ground state and semidirect decay to the low-lying (2{sup +},5{sup -}, and 3{sup -}) phonon states in {sup 90}Zr were observed. It was found that these phonon states play an important role in the damping process of the single-particle states. An optical-model coupled-channel approach was used successfully to describe the direct and semidirect parts of the decay.

Authors:
; ; ; ;  [1]; ; ; ; ; ; ; ;  [2];  [3];  [2];  [4]; ;  [5]; ;  [6] more »;  [1];  [7] « less
  1. Kernfysisch Versneller Instituut (KVI), University of Groningen, 9747 AA Groningen (Netherlands)
  2. Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan)
  3. Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
  4. (Japan)
  5. Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)
  6. Institut de Physique Nucleaire, IN2P3-CNRS, F-91406 Orsay Cedex (France)
  7. (Russian Federation) (and others)
Publication Date:
OSTI Identifier:
20990950
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevC.75.014311; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; COUPLED CHANNEL THEORY; DAMPING; DECAY; GROUND STATES; MEV RANGE 100-1000; NIOBIUM 91; OPTICAL MODELS; PARTICLES; PHONONS; PROTONS; ZIRCONIUM 90

Citation Formats

Molen, H. K. T. van der, Berg, A. M. van den, Harakeh, M. N., Hunyadi, M., Kalantar-Nayestanaki, N., Akimune, H., Daito, I., Fujimura, H., Ihara, F., Inomata, T., Ishibashi, K., Yoshida, H., Yosoi, M., Fujita, Y., Fujiwara, M., Advanced Science Research Center, JAERI, Tokai, Ibaraki 319-1195, Jaenecke, J., O'Donnell, T. W., Laurent, H., Lhenry, I., Rodin, V. A., and Department of Theoretical Nuclear Physics, MEPI, RU-115409 Moscow. Damping mechanisms of high-lying single-particle states in {sup 91}Nb. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.014311.
Molen, H. K. T. van der, Berg, A. M. van den, Harakeh, M. N., Hunyadi, M., Kalantar-Nayestanaki, N., Akimune, H., Daito, I., Fujimura, H., Ihara, F., Inomata, T., Ishibashi, K., Yoshida, H., Yosoi, M., Fujita, Y., Fujiwara, M., Advanced Science Research Center, JAERI, Tokai, Ibaraki 319-1195, Jaenecke, J., O'Donnell, T. W., Laurent, H., Lhenry, I., Rodin, V. A., & Department of Theoretical Nuclear Physics, MEPI, RU-115409 Moscow. Damping mechanisms of high-lying single-particle states in {sup 91}Nb. United States. doi:10.1103/PHYSREVC.75.014311.
Molen, H. K. T. van der, Berg, A. M. van den, Harakeh, M. N., Hunyadi, M., Kalantar-Nayestanaki, N., Akimune, H., Daito, I., Fujimura, H., Ihara, F., Inomata, T., Ishibashi, K., Yoshida, H., Yosoi, M., Fujita, Y., Fujiwara, M., Advanced Science Research Center, JAERI, Tokai, Ibaraki 319-1195, Jaenecke, J., O'Donnell, T. W., Laurent, H., Lhenry, I., Rodin, V. A., and Department of Theoretical Nuclear Physics, MEPI, RU-115409 Moscow. Mon . "Damping mechanisms of high-lying single-particle states in {sup 91}Nb". United States. doi:10.1103/PHYSREVC.75.014311.
@article{osti_20990950,
title = {Damping mechanisms of high-lying single-particle states in {sup 91}Nb},
author = {Molen, H. K. T. van der and Berg, A. M. van den and Harakeh, M. N. and Hunyadi, M. and Kalantar-Nayestanaki, N. and Akimune, H. and Daito, I. and Fujimura, H. and Ihara, F. and Inomata, T. and Ishibashi, K. and Yoshida, H. and Yosoi, M. and Fujita, Y. and Fujiwara, M. and Advanced Science Research Center, JAERI, Tokai, Ibaraki 319-1195 and Jaenecke, J. and O'Donnell, T. W. and Laurent, H. and Lhenry, I. and Rodin, V. A. and Department of Theoretical Nuclear Physics, MEPI, RU-115409 Moscow},
abstractNote = {Decay by proton emission from high-lying states in {sup 91}Nb, populated in the {sup 90}Zr({alpha},t) reaction at E{sub {alpha}}=180 MeV, has been investigated. Decay to the ground state and semidirect decay to the low-lying (2{sup +},5{sup -}, and 3{sup -}) phonon states in {sup 90}Zr were observed. It was found that these phonon states play an important role in the damping process of the single-particle states. An optical-model coupled-channel approach was used successfully to describe the direct and semidirect parts of the decay.},
doi = {10.1103/PHYSREVC.75.014311},
journal = {Physical Review. C, Nuclear Physics},
number = 1,
volume = 75,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
  • The neutron decay of high-lying single-particle states in [sup 209]Pb excited by means of the ([alpha],[sup 3]He) reaction has been investigated at 122 MeV incident energy using a multidetector array. The high spin values of these states, inferred from previous inclusive experiments, are confirmed by the present data involving angular correlation measurements and the determination of branching ratios to low lying levels in [sup 208]Pb. The structure located between 8.5 and 12 MeV excitation energy in [sup 209]Pb displays large departures from a pure statistical decay with significant direct feeding of the low-lying collective states (3[sup [minus]],5[sup [minus]]) of [supmore » 208]Pb. At higher excitation energy up to 20 MeV, the measured neutron decay is in agreement with the predictions of the statistical model.« less
  • The properties of high-spin states in /sup 91/Nb and /sup 91/Zr have been studied with the /sup 88/Sr(/sup 6/Li, 3n)/sup 91/Nb and /sup 88/Sr(/sup 6/Li, p2 n)/sup 91/Zr reactions. In-beam measurements with Ge(Li) and Si(Li) detectors of ..gamma..-ray excitation functions, ..gamma..-..gamma.. coincidences, ..gamma..-ray angular distributions, and pulsed beam-..gamma.. timing spectra were made to establish decay schemes, level energies, spin-parity assignments, ..gamma..-ray multipolarities, and isomeric lifetimes. All of the high-spin states involving the ..pi..1g/sub 9///sub 2/, ..pi..2p/sub 1///sub 2/, and ..nu..2d/sub 5///sub 2/ orbitals as well as other more complicated states were identified. In particular, the theoretically predicted isomeric states inmore » /sup 91/Nb and /sup 91/Zr were found: the vertical-bar (1g/sub 9///sub 2/)/sup 2/2p/sub 1///sub 2/, 17/2/sup -/> state in /sup 91/Nb is at 2035 keV with a tau = 5.42 +- 0.18 ..mu..sec, and vertical-bar (1g/sub 9///sub 2/) /sup 2/2d/sub 5///sub 2/, 21/2/sup +/> state in /sup 91/Zr is at 3167 keV with a tau = 6.28 +- 0.20 ..mu..sec. The experimental energy levels and B (E2) values (E2 effective charges) obtained for these nuclei as well as those of other N = 50 and 51 nuclei are compared with recent theoretical work of Gloeckner et al. (AIP)« less