WorldWideScience

Sample records for e4-transitions

  1. Validity of the adiabatic rotational model in the case of the Hexadecupole operator

    International Nuclear Information System (INIS)

    Sharma, S.K.; Raina, P.K.

    1989-06-01

    The validity of the rotational model expressions relating the E4 transition probabilities and the intrinsic hexadecupole moments is examined in the light of the recent data on the inelastic electron-scattering form factors for the 0 + → 4 + transitions in some medium-mass nuclei. (author). 14 refs, 2 figs, 2 tabs

  2. Sdg interacting-boson model in the SU(3) scheme and its application to /sup 168/Er

    International Nuclear Information System (INIS)

    Yoshinaga, N.; Akiyama, Y.; Arima, A.

    1988-01-01

    The sdg interacting-boson model is presented in the SU(3) tensor formalism. The interactions are decomposed according to their SU(3) tensor character. The existence of the SU(3)-seniority preserving operator is found to be important. The model is applied to /sup 168/Er. Energy levels and electromagnetic transitions are calculated. This model is shown to solve the problem of anharmonicity regarding the excitation energy of the first K/sup π/ = 4 + band relative to that of the first K/sup π/ = 2 + one. E4 transitions are calculated to give different predictions from those by the quasiparticle-phonon nuclear model

  3. Description of transitional nuclei in the sdg boson model

    International Nuclear Information System (INIS)

    Lac, V.S.; Kuyucak, S.

    1992-01-01

    The study of the transitional nuclei in the framework of the sdg boson model was necessitated by recent measurements of E2 and E4 transitions in the Pt and Os isotopes which can not be explained in the sd boson models. It is shown how γ-unstable and triaxial shapes arise from special choices of sdg model Hamiltonians. Ways of limiting the number of free parameters through consistency and coherence conditions are also discussed. A satisfactory description of E2 and E4 properties is obtained for the Pt and Os nuclei, which also predicts dynamic shape transitions in these nuclei. 36 refs., 10 tabs., 12 figs

  4. Description of transitional nuclei in the sdg boson model

    International Nuclear Information System (INIS)

    Lac, V.S.; Kuyucak, S.

    1992-01-01

    We study the transitional nuclei in the framework of the sdg boson model. This extension is necessitated by recent measurements of E2 and E4 transitions in the Pt and Os isotopes which can not be explained in the sd boson models. We show how γ-unstable and triaxial shapes arise from special choices of sdg model hamiltonians and discuss ways of limiting the number of free parameters through consistency and coherence conditions. A satisfactory description of E2 and E4 properties is obtained for the Pt and Os nuclei, which also predicts dynamic shape transitions in these nuclei. (orig.)

  5. sdg interacting-boson model in the SU(3) scheme and its application to 168Er

    Science.gov (United States)

    Yoshinaga, N.; Akiyama, Y.; Arima, A.

    1988-07-01

    The sdg interacting-boson model is presented in the SU(3) tensor formalism. The interactions are decomposed according to their SU(3) tensor character. The existence of the SU(3)-seniority preserving operator is found to be important. The model is applied to 168Er. Energy levels and electromagnetic transitions are calculated. This model is shown to solve the problem of anharmonicity regarding the excitation energy of the first Kπ=4+ band relative to that of the first Kπ=2+ one. E4 transitions are calculated to give different predictions from those by the quasiparticle-phonon nuclear model.

  6. Description of transitional nuclei in the sdg boson model

    Science.gov (United States)

    Lac, V.-S.; Kuyucak, S.

    1992-03-01

    We study the transitional nuclei in the framework of the sdg boson model. This extension is necessitated by recent measurements of E2 and E4 transitions in the Pt and Os isotopes which can not be explained in the sd boson models. We show how γ-unstable and triaxial shapes arise from special choices of sdg model hamiltonians and discuss ways of limiting the number of free parameters through consistency and coherence conditions. A satisfactory description of E2 and E4 properties is obtained for the Pt and Os nuclei, which also predicts dynamic shape transitions in these nuclei.

  7. Description of transitional nuclei in the sdg boson model

    Energy Technology Data Exchange (ETDEWEB)

    Lac, V.S.; Kuyucak, S. (School of Physics, Univ. Melbourne, Victoria (Australia))

    1992-03-30

    We study the transitional nuclei in the framework of the sdg boson model. This extension is necessitated by recent measurements of E2 and E4 transitions in the Pt and Os isotopes which can not be explained in the sd boson models. We show how {gamma}-unstable and triaxial shapes arise from special choices of sdg model hamiltonians and discuss ways of limiting the number of free parameters through consistency and coherence conditions. A satisfactory description of E2 and E4 properties is obtained for the Pt and Os nuclei, which also predicts dynamic shape transitions in these nuclei. (orig.).

  8. The contribution of Skyrme Hartree-Fock calculations to the understanding of the shell model

    International Nuclear Information System (INIS)

    Zamick, L.

    1984-01-01

    The authors present a detailed comparison of Skyrme Hartree-Fock and the shell model. The H-F calculations are sensitive to the parameters that are chosen. The H-F results justify the use of effective charges in restricted model space calculations by showing that the core contribution can be large. Further, the H-F results roughly justify the use of a constant E2 effective charge, but seem to yield nucleus dependent E4 effective charges. The H-F can yield results for E6 and higher multipoles, which would be zero in s-d model space calculations. On the other side of the coin in H-F the authors can easily consider only the lowest rotational band, whereas in the shell model one can calculate the energies and properties of many more states. In the comparison some apparent problems remain, in particular E4 transitions in the upper half of the s-d shell

  9. Spectroscopy of samarium isotopes in the sdg interacting boson model

    International Nuclear Information System (INIS)

    Devi, Y.D.; Kota, V.K.B.

    1992-01-01

    Successful spectroscopic calculations for the 0 1 + , 2 1 + , and 4 1 + levels in 146-158 Sm are carried out in sdg boson space with the restriction that the s-boson number n s ≥2 and the g-boson number n g ≤2. Observed energies, quadrupole and magnetic moments, E2 and E4 transition strengths, nuclear radii, and two-nucleon transfer intensities are reproduced with a simple two-parameter Hamiltonian. For a good simultaneous description of ground, β, and γ bands, a Hamiltonian interpolating the dynamical symmetries in the sdg model is employed. Using the resulting wave functions, in 152,154 Sm, the observed B(E4;0 1 + →4 γ + ) values are well reproduced and E4 strength distributions are predicted. Moreover, a particular ratio scrR involving two-nucleon transfer strengths showing a peak at neutron number 90 is well described by the calculations

  10. γ-unstable nuclei in the sdg boson model

    International Nuclear Information System (INIS)

    Kuyucak, S.; Lac, V-S.; Morrison, I.; Barret, B.R.

    1991-01-01

    Following the recent Pt(p,p') experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a γ-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the γ-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4 + states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes. 12 refs., 2 tabs., 4 figs

  11. gamma. -unstable nuclei in the sdg boson model

    Energy Technology Data Exchange (ETDEWEB)

    Kuyucak, S.; Lac, V.S.; Morrison, I.; Barrett, B.R. (School of Physics, Univ. of Melbourne, Parkville (Australia))

    1991-07-18

    Following the recent Pt(p, p') experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to include g bosons. It is shown that a {gamma}-unstable hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the {gamma}-unstable nature of the hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions. Applications are made to the Xe and Pt isotopes. (orig.).

  12. Gamma-unstable nuclei in the sdg boson model

    Science.gov (United States)

    Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barret, B. R.

    Following the recent Pt(p,p') experiments which indicated the need for high angular momentum (g) bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to the sdg bosons. It is shown that a gamma-unstable Hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the gamma-unstable nature of the Hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions to the 4(sup +) states presumed to be g boson states. Specific applications are made to the Xe and Pt isotopes.

  13. γ-unstable nuclei in the sdg boson model

    Science.gov (United States)

    Kuyucak, S.; Lac, V.-S.; Morrison, I.; Barrett, B. R.

    1991-07-01

    Following the recent Pt(p, p‧) experiments which indicated the need for g bosons to reproduce the E4 data, we have extended the O(6) limit of the sd boson model to include g bosons. It is shown that a γ-unstable hamiltonian in the sdg model consisting of a quadrupole interaction and a g boson energy leads to results that are very similar to the O(6) limit. Deviations from the empirical energy spectrum that stem from the γ-unstable nature of the hamiltonian can be improved by including a consistent hexadecapole interaction which induces triaxiality. The same hexadecapole operator can also account for the strong E4 transitions. Applications are made to the Xe and Pt isotopes.

  14. Study on 9Be(#betta#, n) reaction

    International Nuclear Information System (INIS)

    Fujishiro, M.; Tabata, T.; Satoh, Y.; Furuta, J.; Okamoto, K.

    1982-01-01

    In chapter 1 are described measurements of cross sections σ(E sub(#betta#)) of the 9 Be(#betta#, n) reaction with six kinds of radioisotopes. The results were σ(1674.7) = 8.8 +- 1.6, σ(1705.2) = 13.3 +- 2.4, σ(1724.9) = 11.0 +- 2.0, σ(1778.9) = 7.3 +- 1.3, σ(1836.0) = 4.7 +- 0.9, and σ(2167.6) = 1.8 +- 0.4 in unit of 10 - 28 cm 2 . The cross sections measured show a cusp-like peak near the threshold, and its width is narrower than that observed by Jakobson with bremsstrahlung X-rays. Comparison of the present results with theories indicates that mutual agreement is yet qualitative. In chapter 2 is described a measurement of the intensity I(2009.8) of the crossover E4 transition in 46 Ti by applying the 9 Be(#betta#, n) reaction. The observed intensity per decay of 46 Sc was I(2009.8) = (1.2 +- 0.7) x 10 - 7 . From the present result the reduced transition probability B(E4) of the crossover E4 transition between the 2009.8 keV, 4 + excited state and the 0 + ground state of 46 Ti was estimated as B(E4) = (5.2 +- 3.7) x 10 - 99 e 2 .cm 8 . Discussion was given of the presently measured intensity and of nuclear models. (author)

  15. Polynomial expansions and transition strengths

    International Nuclear Information System (INIS)

    Draayer, J.P.

    1980-01-01

    The subject is statistical spectroscopy applied to determining strengths and strength sums of excitation processes in nuclei. The focus will be on a ds-shell isoscalar E2 study with detailed shell-model results providing the standard for comparison; similar results are available for isovector E2 and M1 and E4 transitions as well as for single-particle transfer and ν +- decay. The present study is intended to serve as a tutorial for applications where shell-model calculations are not feasible. The problem is posed and a schematic theory for strengths and sums is presented. The theory is extended to include the effect of correlations between H, the system Hamiltonian, and theta, the excitation operator. Associated with correlation measures is a geometry that can be used to anticipate the goodness of a symmetry. This is illustrated for pseudo SU(3) in the fp-shell. Some conclusions about fluctuations and collectivity that one can deduce from the statistical results for strengths are presented

  16. Internal conversion coefficients of high multipole transitions: Experiment and theories

    International Nuclear Information System (INIS)

    Gerl, J.; Vijay Sai, K.; Sainath, M.; Gowrishankar, R.; Venkataramaniah, K.

    2008-01-01

    A compilation of the available experimental internal conversion coefficients (ICCs), α T , α K , α L , and ratios K/L and K/LM of high multipole (L > 2) transitions for a number of elements in the range 21 ≤ Z ≤ 94 is presented. Our listing of experimental data includes 194 data sets on 110 E3 transitions, 10 data sets on 6 E4 transitions, 11 data sets on 7 E5 transitions, 38 data sets on 21 M3 transitions, and 132 data sets on 68 M4 transitions. Data with less than 10% experimental uncertainty have been selected for comparison with the theoretical values of Hager and Seltzer [R.S. Hager, E.C. Seltzer, Nucl. Data Tables A 4 (1968) 1], Rosel et al. [F. Roesel, H.M. Fries, K. Alder, H.C. Pauli, At. Data Nucl. Data Tables 21 (1978) 91], and BRICC. The relative percentage deviations (%Δ) have been calculated for each of the above theories and the averages (%Δ-bar) are estimated. The Band et al. [I.M. Band, M.B. Trzhaskovskaya, C.W. Nestor Jr., P.O. Tikkanen, S. Raman, At. Data Nucl. Data Tables 81 (2002) 1] tables, using the BRICC interpolation code, are seen to give theoretical ICCs closest to experimental values