共查询到20条相似文献,搜索用时 31 毫秒
1.
W. Urban T. Rzaca-Urban N. Schulz J.L. Durell W.R. Phillips A.G. Smith B.J. Varley I. Ahmad 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):303-307
Excited levels in 140Xe and 142Xe nuclei, populated in the spontaneous fission of 248Cm, were studied by means of prompt γ-ray spectroscopy, using EUROGAM2 array. We report the first observation of an octupole
band in 142Xe and extend the octupole band in 140Xe. Level schemes of 140Xe and 142Xe obtained in this work show patterns characteristic of ocupole-vibrational bands. Properties of octupole bands in Xe isotopes
indicate that octupole correlations in these nuclei are lower than in the corresponding Ba nuclei. The electric dipole moment
of 142Xe was found to be larger than in other Xe isotopes, contrary to theoretical predictions. This may be due to the special role
of the N = 88 neutron number.
Received: 18 November 2002 / Accepted: 15 December 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: urban@fuw.edu.pl
Communicated by D. Schwalm 相似文献
2.
S. Singh R. Chandra P. K. Rath P. K. Raina J. G. Hirsch 《The European Physical Journal A - Hadrons and Nuclei》2007,33(4):375-388
The two-neutrino double-beta decay of 124, 126Xe , 128, 130Te , 130, 132Ba and 150Nd isotopes is studied in the Projected Hartree-Fock-Bogoliubov (PHFB) model. Theoretical 2ν β-β- half-lives of 128, 130Te , and 150Nd isotopes, and 2ν β+β+ , 2ν β+
EC and 2ν ECEC for 124, 126Xe and 130, 132Ba nuclei are presented. Calculated quadrupolar transition probabilities B(E2 : 0+ → 2+) , static quadrupole moments and g -factors in the parent and daughter nuclei reproduce the experimental information, validating the reliability of the model
wave functions. The anticorrelation between nuclear deformation and the nuclear transition matrix element M
2ν is confirmed. 相似文献
3.
J.H. Hamilton A.V. Ramayya J.K. Hwang X.Y. Luo J.O. Rasmussen E.F. Jones X.Q. Zhang S.J. Zhu P.M. Gore T.N. Ginter I.Y. Lee R.V.F. Janssens I. Ahmed J.D. Cole W. Greiner G. Ter-Akopian Yu. Oganessian 《The European Physical Journal A - Hadrons and Nuclei》2002,15(1-2):175-179
With new high statistic data, new isotopes and new high-spin structures are observed in neutron-rich nuclei populated in the
spontaneous fission of 252Cf. The 135Te levels are extended, and many new levels in 139,141Ba observed. The coexistence of collective and single particle-hole states is found in 135Te. The N = 83 135Te and 139Ba show marked differences associated with differences in their particle and hole states. New levels in 141Ba complete evidence for two opposite-parity doublets characteristic of stable octupole deformation. In 114,116Pd a second backbend is observed for the first time in this mass region and the backbend in 118Pd occurs earlier than in 112-116Pd because of a reduction in pairing. Gamma-type vibrational bands are seen up to 13+ to 15+ in 104,106Mo, 108-112Ru, and 112-116Pd. Their behavior reflects prolate to triaxial shapes in these nuclei. The levels of 162,164Gd are observed for the first time. As N increases toward mid-shell at 104, the moments of inertia in N = 100 164Gd show an unexpected decrease compared to N = 98 162Gd. The levels in 162,164Gd form remarkable shifted identical bands with nuclei separated by 2n, 2p, α, and 2α.
Received: 21 March 2002 / Accepted: 16 May 2002 / Published online: 31 October 2002
RID="a"
ID="a"e-mail: j.h.hamilton@vanderbilt.edu 相似文献
4.
K. Singh S. Sihotra S. S. Malik J. Goswamy D. Mehta N. Singh R. Kumar R. P. Singh S. Muralithar E. S. Paul J. A. Sheikh C. R. Praharaj 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):321-324
The collective band structures of the 125Cs nucleus have been investigated by in-beam γ-ray spectroscopic techniques following the 110Pd ( 19F, 4n) reaction at 75MeV. The previously known level scheme, with rotational bands built on πg7/2, πg9/2 and πh11/2 orbitals, has been extended and evolves into bands involving rotationally aligned ν(h11/2)2 and π(h11/2)2 quasiparticles. A strongly coupled band has been reassigned a high-K πh11/2 ⊗ νg7/2 ⊗ νh11/2 three-quasiparticle configuration and a new side band likely to be its chiral partner has been identified. Configurations
assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model calculations. 相似文献
5.
The configuration-dependent cranked Nilsson-Strutinsky approach has been employed to study the properties and band structures
at high spin in the Z = N odd-odd nuclei 46V and 50Mn. The observed bands are explained and terminating states are confirmed by the calculations. The calculated and observed
bands are in good agreement without normalization, especially for terminating states. Possible bands with rotation around
the intermediate axis and the effect of γ-deformation on the total energy of several interesting configurations are discussed.
Received: 2 April 2002 / Accepted: 27 January 2003 / Published online: 15 April 2003 相似文献
6.
W. Urban N. Schulz M. Bentaleb E. Lubkiewicz J. L. Durell M. J. Leddy M. A. Jones W. R. Phillips A. G. Smith B. J. Varley I. Ahmad L. R. Morss 《The European Physical Journal A - Hadrons and Nuclei》2000,8(1):5-7
Excited levels in 141Xe, populated in spontaneous fission of 248Cm, were studied by means of prompt -ray spectroscopy, using the EUROGAMM2 array. Level scheme of 141Xe obtained in this work shows patterns characteristic of simplex symmetry with s=+i and s=-i bands present but low value of D0 moment indicates that octupole correlations in Xe isotopes are systematically lower than in Ba nuclei.
Received: 9 March 2000 / Accepted: 4 May 2000 相似文献
7.
C.-B. Moon T. Komatsubara Y. Sasaki T. Jumatsu K. Yamada K. Satou K. Furuno 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):13-16
Excited states of the 119Xe nucleus have been studied by using in-beam γ-ray spectroscopy with the 107Ag ( 16O, p3n) 119Xe fusion-evaporation reaction at a beam energy of 85 MeV. The level scheme of 119Xe has been derived from γ-γ coincidence and γ-γ angular correlation analyses. We have, for the first time, established the
second negative-parity favored and unfavored states built on the 11/2- state, namely the yrare rotational bands in 119Xe. In contrast to the behavior of the yrast bands where the favored states are lying lower in energy, the yrare favored states
were observed to lie above the unfavored band. Such a signature inversion in 119Xe is changed to be normal at I = 12?.
Received: 8 January 2002 / Accepted: 18 April 2002 相似文献
8.
D. Ringkjøbing Jensen J. Domscheit G. B. Hagemann M. Bergström B. Herskind B. S. Nielsen G. Sletten P. G. Varmette S. Törmänen H. Hübel W. Ma A. Bracco F. Camera F. Demaria S. Frattini B. Million D. Napoli A. Maj B. M. Nyakó D. T. Joss M. Aiche 《The European Physical Journal A - Hadrons and Nuclei》2000,8(2):165-176
The nucleus 166Hf has been populated by the reaction 96Zr(74Ge,4n) using a beam energy of 310MeV. γ-rays were detected with the EUROBALL III detector array. Fourteen new normal-deformed rotational bands, of which six form
coupled pairs, have been observed in 166Hf. Four previously known bands have been extended to considerably higher spin, and configurations of the new bands are proposed.
Two different bands have been assigned configurations involving the same orbitals at high spin. The two coupling schemes,
deformation and rotation alignment, are discussed in connection with this new observation, which calls for a formulation of
co-existing coupling schemes in six-quasiparticle structures involving the same orbitals at high spin. 相似文献
9.
A. Dhal R. K. Sinha P. Agarwal S. Kumar Monika B. B. Singh R. Kumar P. Bringel A. Neusser R. Kumar K. S. Golda R. P. Singh S. Muralithar N. Madhavan J. J. Das A. Shukla P. K. Raina K. S. Thind A. K. Sinha I. M. Govil P. K. Joshi R. K. Bhowmik A. K. Jain S. C. Pancholi L. Chaturvedi 《The European Physical Journal A - Hadrons and Nuclei》2006,27(1):33-36
High-spin states in 78Kr have been studied via the 63Cu (19F, 2p2n)78Kr reaction at a beam energy of 60 MeV using the Indian National Gamma Array (INGA). In this nucleus, lifetimes have been
measured upto the Iπ=22+ level in the yrast positive-parity band and upto the Iπ=15- level in the negative-parity band using the Doppler Shift Attenuation Method (DSAM). The deduced transition quadrupole moments
Qt's are found to decrease with rotational frequency for both the bands. 相似文献
10.
D. Bucurescu G. Căta-Danil I. Căta-Danil M. Ivaşcu N. Mărginean R. Mărginean L. C. Mihăilescu C. Rusu G. Suliman 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):301-312
Gamma-ray coincidence techniques are used to determine new level structures in the N = 81 nucleus 139Ce, at low spins and excitation energies with the 139La(p, nγ) reaction at 5.0 and 6.0MeV incident energy, and at high spins with the 130Te(12C, 3nγ) reaction at 50.5MeV, respectively. Lifetime determinations are also made in the (p, nγ) reaction with the centroid DSA method. The observed level structures are discussed by comparison with existing calculations
and with those in the neighbouring nucleus 140Ce. 相似文献
11.
A. Görgen E. Clément A. Chatillon A. Dewald W. Korten Y. Le Coz N. Mărginean B. Melon R. Menegazzo O. Möller Ch. Theisen D. Tonev C. A. Ur K. O. Zell 《The European Physical Journal A - Hadrons and Nuclei》2005,26(2):153-157
Lifetimes of excited states in the ground-state bands of 74Kr and 76Kr were measured using the recoil-distance Doppler-shift and the differential decay curve methods. The states were populated
in the 40Ca(40Ca, α2p) and 40Ca(40Ca, 4p) reactions. Gamma rays were detected with the GASP array which was coupled to the Cologne Plunger device. The results resolve
discrepancies between earlier lifetime measurements and a recent Coulomb excitation experiment. Experimental transition rates
are compared to theoretical calculations. The results support a strong mixing between prolate and oblate configurations for
the low-spin states, and represent an important basis for the interpretation and understanding of the shape coexistence phenomenon
in this mass region. 相似文献
12.
T. Hayakawa Y. Toh M. Oshima M. Matsuda Y. Hatsukawa J. Katakura H. Iimura T. Shizuma S. Mitarai M. Sugawara H. Kusakari Y.H. Zhang 《The European Physical Journal A - Hadrons and Nuclei》2002,15(3):299-302
High-spin states of 157Dy were investigated using in-beam γ-ray spectroscopy techniques with a 150Nd(12C, 5n) reaction. Three rotational bands with the h
9/2, i
13/2 and h
11/2 configurations were observed up to (43/2-), 53/2+ and 45/2-, respectively. Interband M1 transitions in the h
11/2 (high-Ω) band were also measured up to the highest-spin state. The high-spin states were well reproduced by calculations
using the tilted-axis-cranking model (TAC). The B(M1)/B(E2) ratio, Routhian and the tilted angle of the angular-momentum vector are found to be in good agreement with the result of
the TAC calculation.
Received: 22 August 2002 / Accepted: 26 September 2002 / Published online: 19 November 2002
RID="a"
ID="a"e-mail: hayakawa@jball4.tokai.jaeri.go.jp
Communicated by W. Henning 相似文献
13.
M.-G. Porquet Ts. Venkova P. Petkov A. Bauchet I. Deloncle A. Astier N. Buforn J. Duprat B.J.P. Gall C. Gautherin E. Gueorguieva F. Hoellinger T. Kutsarova R. Lucas M. Meyer A. Minkova N. Redon N. Schulz H. Sergolle A. Wilson 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):463-470
The 106, 108Rh and 110, 112Ag nuclei have been produced as fission fragments following the fusion reaction 28Si + 176Yb at 145 MeV bombarding energy and studied with the Eurogam2 array. The yrast high-spin states of these four odd-odd nuclei,
which are observed for the first time, consist of rotational bands in which the odd proton occupies the πg
9/2 subshell and the odd neutron the νh
11/2 subshell. Their behaviour as a function of spin values does not vary with the number of neutrons: as observed in the odd-N neighbouring nuclei, the motion of the odd neutron remains decoupled from the motion of the core, from N = 61 to N = 65. Moreover, the staggering observed in the yrast bands of odd-odd isotopes is strongly reduced as compared to the large
values displayed by the rotational bands built on the πg
9/2 subshell in the odd-A Rh and Ag isotopes. The results of particle-rotor calculations indicate that this reduction is related to a change of the
core deformation.
Received: 1 June 2001 / Accepted: 23 July 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: porquet@csnsm.in2p3.fr
RID="b"
ID="b"Present address: CSNSM IN2P3-CNRS and Université Paris-Sud 91405 Orsay, France.
RID="c"
ID="c"Present address: NAC, Faure, ZA 7131, South Africa.
RID="d"
ID="d"Present address: Department of Nuclear Physics, ANU, Canberra ACT 0200, Australia.
Communicated by D. Schwalm 相似文献
14.
C. Wheldon Tz. Kokalova W. von Oertzen S. Thummerer H. G. Bohlen B. Gebauer A. Tumino T. N. Massey G. de Angelis M. Axiotis A. Gadea Th. Kröll N. Mărginean D. R. Napoli M. De Poli C. Ur D. Bazzacco S. M. Lenzi C. Rossi Alvarez S. Lunardi R. Menegazzo P. G. Bizzeti A. M. Bizzeti-Sona 《The European Physical Journal A - Hadrons and Nuclei》2005,26(3):321-326
Cluster states up to 12 MeV in the stable light nucleus 21Ne, based on the 16O + n + α molecular configurations, have been populated in the incomplete-fusion reaction 16 8O(73Li, np)2110Ne at 29.4 MeV. The observation of both intra- and inter-band transitions leads to a re-interpretation of some levels in the
Kπ =
- and Kπ =
- bands. The implications of this re-ordering on the octupole doublet bands are examined. The data allow a more accurate determination
of some previously uncertain level energies. The “missing” Iπ =
- level is also discussed. 相似文献
15.
C.M. Petrache G. Lo Bianco P.G. Bizzeti A.M. Bizzeti-Sona D. Bazzacco S. Lunardi M. Nespolo G. de Angelis D.R. Napoli N. Blasi S. Brant D. Vretenar 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):337-346
The even-even nucleus 126Ce was studied via in-beam γ-ray spectroscopy using the 40Ca + 92Mo reaction at 190 MeV. Five bands were observed, one of them being identified for the first time. New connecting transitions
were identified between the bands, which lead to new spin assignments. The bands are discussed in the framework of the IBM
+ broken pairs model.
Received: 17 July 2002 / Accepted: 23 October 2002 / Published online: 18 February 2003
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
Communicated by C. Signorini 相似文献
16.
E. Mergel C.M. Petrache G. Lo Bianco H. Hübel J. Domscheit D. Roßbach G. Schönwaßer N. Nenoff A. Neußer A. Görgen F. Becker E. Bouchez M. Houry A. Hürstel Y. Le Coz R. Lucas Ch. Theisen W. Korten A. Bracco N. Blasi F. Camera S. Leoni F. Hannachi A. Lopez-Martens M. Rejmund D. Gassmann P. Reiter P.G. Thirolf A. Astier N. Buforn M. Meyer N. Redon O. Stezowski 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):417-420
The even-even nucleus 136Nd was studied via in-beam γ-ray spectroscopy using the 16O + 125Te reaction at 100 MeV and the EUROBALL array. One new dipole band was observed. Together with a previously identified dipole
band, whose position in the level scheme is revised, the new band forms a doublet structure similar to the recently observed
chiral bands in the odd-odd neighboring nuclei. This would be the first case of a chiral doublet in an even-even nucleus.
Received: 23 May 2002 / Accepted: 30 September 2002 / Published online: 27 November 2002
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
RID="b"
ID="b"Present address: Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
RID="c"
ID="c"Present address: Gesellschaft für Schwerionenforschung D-64291 Darmstadt, Germany.
Communicated by C. Signorini 相似文献
17.
R. K. Sinha A. Dhal P. Agarwal S. Kumar Monika B. B. Singh R. Kumar P. Bringel A. Neusser R. Kumar K. S. Golda R. P. Singh S. Muralithar N. Madhavan J. J. Das K. S. Thind A. K. Sinha I. M. Govil R. K. Bhowmik J. B. Gupta P. K. Joshi A. K. Jain S. C. Pancholi L. Chaturvedi 《The European Physical Journal A - Hadrons and Nuclei》2006,28(3):277-281
High-spin states in 79Rb were populated in the reaction
at E(beam) = 60 MeV. The lifetimes of the excited states of the
positive-parity yrast band and of the
negative-parity band in 79Rb were measured by the Doppler Shift Attenuation Method. The deduced transition quadrupole moments Qt are found to have a decreasing trend with rotational frequency for both the bands, consistent with those found experimentally
in neighbouring nuclei.
An erratum to this article is available at . 相似文献
18.
T. Bäck B. Cederwall K. Lagergren R. Wyss A. Johnson P. Greenlees D. Jenkins P. Jones D.T. Joss R. Julin S. Juutinen A. Keenan H. Kettunen P. Kuusiniemi M. Leino A.-P. Leppänen M. Muikku P. Nieminen J. Pakarinen P. Rahkila J. Uusitalo 《The European Physical Journal A - Hadrons and Nuclei》2003,17(1):1-5
The decay out of the πh
11/2νh
11/2 band to the known low-energy levels in 132La was studied using the reaction 100Mo + 36S at 160 MeV beam energy. The low-energy level scheme has been further developed and unambiguous spin and parity values have
been assigned to the levels connecting the band to the 6- isomeric state. According to the new level scheme the spins in the πh
11/2νh
11/2 band are shifted up by one unit compared to the earlier tentative experimental values. The obtained new spins prove the existence
of signature inversion in 132La and give further support to the spin assignments made for the πh
11/2νh
11/2 bands in the neighbouring odd-odd La isotopes from level energy systematics.
Received: 7 May 2002 / Accepted: 31 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: timar@atomki.hu
RID="b"
ID="b"Present address: Dipartimento di Matematica e Fisica, Università di Camerino, via Madonna delle Carceri, I-62032 Camerino, Italy.
Communicated by J. ?yst? 相似文献
19.
K. Van de Vel A.N. Andreyev R.D. Page H. Kettunen P.T. Greenlees P. Jones R. Julin S. Juutinen H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino M. Muikku P. Nieminen P. Rahkila J. Uusitalo K. Eskola A. Hürstel M. Huyse Y. Le Coz M.B. Smith P. Van Duppen R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):167-171
Gamma rays from excited states of 190Po have been observed using the Jurosphere Ge-detector array coupled to the RITU gas-filled separator. They were associated
with a collective band which from spin 4 onwards resembles the prolate rotational bands known in the isotones 188Pb and 186Hg. This indicates that in 190Po the prolate configuration becomes yrast above I = 2. The experimental results are interpreted in a two-band mixing calculation and are in agreement with α-decay data and
potential energy surface calculations.
Received: 10 January 2003 / Accepted: 19 February 2003 / Published online: 7 May 2003 相似文献
20.
E. O. Lieder A. A. Pasternak R. M. Lieder A. D. Efimov V. M. Mikhajlov B. G. Carlsson I. Ragnarsson W. Gast Ts. Venkova T. Morek S. Chmel G. de Angelis D. R. Napoli A. Gadea D. Bazzacco R. Menegazzo S. Lunardi W. Urban Ch. Droste T. Rzaca-Urban G. Duchêne A. Dewald 《The European Physical Journal A - Hadrons and Nuclei》2008,35(2):135-158
For a level scheme investigation of 142Gd an experiment with the γ -spectrometer EUROBALLIII has been carried out and lifetimes have been measured with EUROBALL
IV using the Doppler-shift attenuation method. The high-spin states have been populated in these experiments by means of the
99Ru(48Ti, 2p3n) reaction at a beam energy of 240MeV and the 114Sn(32S, 2p2n) reaction at 160MeV, respectively. Reduced E2 transition probabilities B(E2) were determined for 15 members of four quadrupole bands. For the interpretation of the positive-parity even-spin quadrupole
bands, calculations in the cranked Nilsson-Strutinsky as well as interacting boson models have been performed. From the former
calculations it was concluded that the high-spin states of the (+ , 0)1 band in 142Gd represent a triaxial nucleus rotating around the longest principal axis. 相似文献