High-spin states in 224,226,228Th and the systematics of octupole effects in even Th isotopes

Schüler, P.; Lauterbach, C.; Agarwal, Y.K.; Boer, J. de; Blume, K.P.; Butler, P. A.; Euler, Karl‐Joachim; Fleischmann, Ch.; Günther, C.; Hauber, E.; Maier, H.; Marten-Tölle, M.; Schandera, Ch.; Simon, R. S.; Tölle, R.; Zeyen, P.

doi:10.1016/0370-2693(86)91091-9

Cited by 83 publications

(27 citation statements)

References 15 publications

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“…The most complete information was obtained from the β-decay of 228 Ac reported by Dalmasso et al [2] and from the EC-decay study of 228 Pa by Weber et al [7]. The lowest collective bands in 228 Th were studied in the (α, xnγ)-reaction [8]. A total of 58 levels were reported in [2] and 80 levels were observed in [7] below 2.1 MeV, connected by more than 240 γ-rays that were established in these studies.…”

Section: Information On Excited States Ofmentioning

confidence: 99%

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
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The excitation spectra in the deformed nucleus 228 Th have been studied by means of the (p,t) reaction, using the Q3D spectrograph facility at the Munich Tandem accelerator. The angular distributions of tritons were measured for about 110 excitations seen in the triton spectra up to 2.5 MeV. Firm 0 + assignments are made for 17 excited states by comparison of experimental angular distributions with the calculated ones using the CHUCK3 code. Assignments up to spin 6 + are made for other states. Sequences of states are selected which can be treated as rotational bands and as multiplets of excitations. Moments of inertia have been derived from these sequences, whose values may be considered as evidence of the two-phonon nature of most 0 + excitations. Experimental data are compared with interacting boson model (IBM) and quasiparticle-phonon model (QPM) calculations and with experimental data for 229 Pa.

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Section: Information On Excited States Ofmentioning

confidence: 99%

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
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“…In Fig. 11, the values of 5E/B are plotted against spin I for the nuclei studied in the present work and for 222 Th and 224[ 11,25]. As can be seen in the figure, 5E is quite high at low spin but it decreases as the spin increases and is near zero at 8-9n, indicating increase of octupole correlations with rotation and stabilization of octupole deformation above spin 8n.…”

mentioning

confidence: 71%

Reflection-Asymmetric Shapes in Nuclei

Ahmad¹,

Carpenter²,

Emling

et al. 1990

Exotic Nuclear Spectroscopy

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Soon after the collective nuclear model [1,2] was established, low-lying negative parity states were observed [3] in even-even Ra and Th nuclei from alpha-particle spectroscopic studies. These negative parity levels formed a rotational band with spin sequence 1, 3, 5, and K quantum number 0. Since these states had energies much lower than the expected two quasi-particle states, these were interpreted as octupole vibrations about a spheroidal equilibrium shape. Ever since the discovery of the octupole vibrations, scientists have been thinking about the possibility of octupole deformations in nuclei, that is, nuclei with octupole equilibrium shape. These octupole shapes are symmetric about the Z axis but reflection asymmetric about the XY plane and resemble a Pear.• --. w i : , . £ ,,,.,.. -, ' ; ,.,,_• , T he submitted manutcnpt has been authored bv a contractor of the U. S. Government under contract Na. W-31-109-ENG-3S. Accordingly, the U. S. Government retains a nonexclusive, royalty-free license \n publish or reproduce the published form of this contribution, or allow others to do so, for IK S. Government purposes. MASTERThe octupole deformation or octupole vibration is produced by the long range octupole-octupole correlations. These correlations depend on the r 3 Y3*r^Y3 matrix elements between single particle states with A2. = Aj -3 and the energy difference between them. A look at the shell states ( Fig. 1 with the binding energy of ~10 MeV due to the quadrupole deformation (Fig. 2).It is well known that the rotation of symmetric and asymmetric molecules generate different rotational bands. In the case of the former, the band has 0 + , 2 + , 4 + --level sequence and the latter has 0 + , 1", 2 + , 3", --sequence.Thus the rotation of reflection symmetric and reflection asymmetric nuclei will produce different spectra and these can be used as signature of octupole shape. OCTUPOLE DEFORMATION THE ACTINIDE REGIONIn odd mass nuclei, the two members of the parity doublet have very similar wave functions except the parity. Thus one would expect similar properties for both bands. The data on odd mass nuclei in the mass 224 region can be summarized as follows:1. Parity doublets have been observed in several odd-mass Ra, Ac and Pa nuclei [12][13][14][15]. An example [14] is shown in Fig. 4. The members of the doublets are connected by fast El transitions [15].The B(E1) values in these nuclei are larger than l.OxlO" 3 Weisskopf units (see Fig. 5).3. Alpha decay rates are enhanced to the parity doublet partner of the favored band.4. Coriolis matrix elements and Ml transition rates are attenuated.5. Octupole deformation has also been found at moderate spins [16] in 221 Th and 223 Th.In even-even nuclei, levels with alternating parity have been observed in several Ra and Th nuclei. In general, these are connected by fast El transitions. OCTUPOLE DEFORMATION IN N-88, Z-56 NUCLEIAs shown in Fig. 1, octupole correlations are also expected in the Z~56, N~8Snuclei. However, in these nuclei, spacings for the A2. = 3, Aj =3 le...

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“…. ) [3,4,5,6,47,48,49]. Since a diatomic molecule consisting of two different atoms possesses the same reflection asymmetry, one might think that ∆J = 1 staggering might be present in the rotational bands of such molecules.…”

Section: Ydmentioning

confidence: 99%

“…. ) [3,4,5,6]. 3) In odd nuclei, rotational bands (with K = 1/2) separate into signature partners, i.e.…”

Section: Introductionmentioning

confidence: 99%

Staggering Effects in Nuclear and Molecular Spectra

Bonatsos

Karoussos

Daskaloyannis

et al. 2001

New Trends in Quantum Systems in Chemistry and Physics

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It is shown that the recently observed ∆J = 2 staggering effect (i.e. the relative displacement of the levels with angular momenta J, J + 4, J + 8, . . . , relatively to the levels with angular momenta J + 2, J + 6, J + 10, . . . ) seen in superdeformed nuclear bands is also occurring in certain electronically excited rotational bands of diatomic molecules (YD, CrD, CrH, CoH), in which it is attributed to interband interactions (bandcrossings). In addition, the ∆J = 1 staggering effect (i.e. the relative displacement of the levels with even angular momentum J with respect to the levels of the same band with odd J) is studied in molecular bands free from ∆J = 2 staggering (i.e. free from interband interactions/bandcrossings). Bands of YD offer evidence for the absence of any ∆J = 1 staggering effect due to the disparity of nuclear masses, while bands of sextet electronic states of CrD demonstrate that ∆J = 1 staggering is a sensitive probe of deviations from rotational behaviour, due in this particular case to the spin-rotation and spin-spin interactions.

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High-spin states in 224,226,228Th and the systematics of octupole effects in even Th isotopes

Cited by 83 publications

References 15 publications

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
View full text Add to dashboard Cite

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
View full text Add to dashboard Cite

Reflection-Asymmetric Shapes in Nuclei

Staggering Effects in Nuclear and Molecular Spectra

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High-spin states in 224,226,228Th and the systematics of octupole effects in even Th isotopes

Cited by 83 publications

References 15 publications

0+states and collective bands in228Th studied by the (p,Levon1, Graw2, Hertenberger3 et al. 2013Phys. Rev. C269700View full textAdd to dashboardCite

0+states and collective bands in228Th studied by the (p,Levon1, Graw2, Hertenberger3 et al. 2013Phys. Rev. C269700View full textAdd to dashboardCite

Reflection-Asymmetric Shapes in Nuclei

Staggering Effects in Nuclear and Molecular Spectra

Contact Info

Product

Resources

About

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
View full text Add to dashboard Cite

0+states and collective bands in228Th studied by the (p,
Levon
¹
,
Graw
²
,
Hertenberger
³

et al. 2013
Phys. Rev. C
26
9
70
0
View full text Add to dashboard Cite