Magnetic dipole strength in 16O

doi:10.1016/0370-2693(80)90203-8

Physics Letters B

Volume 96, Issues 1–2, 20 October 1980, Pages 23-25

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Abstract

The strength of magnetic dipole excitation from the ¹⁶O ground state is calculated. One anticipates a relatively large amount of the M1 strength between 16 MeV and 18 MeV which is about one third of that of the 15.1 MeV, 1⁺ state in ¹²C.

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Cited by (18)

Sum rules and giant resonances in nuclei
1989, Physics Reports
The formalism of sum rules is developed and employed to investigate various giant resonances in nuclei. Particular emphasis is given to the role of surface effects which are shown to play a crucial role in the propagation of isoscalar as well as isovector collective modes. Sum rules for non-Hermitian operators, in particular for charge exchange reactions, are derived using the formalism of the dynamic polarizability. Several sum rules for investigating magnetic excitations, the structure of the transition density and the role of the nuclear deformation and of temperature on giant resonance are also presented and discussed.
Nuclear structure of 16O in a mean-field boson approach
1988, Physics Letters B
It is shown that a combined use of the mean-field approximation (MFA) and the Belyaev-Zelevinsky-Marshalek (BZM) boson image of the shell-model hamiltonian may provide a reasonably accurate simulataneous description of the total binding energy, excitation spectra up to 12 MeV (both the positive-parity and the negative-parity ones) and the electron scattering form-factors for ¹⁶O. Comparison with the shell-model results obtained in a restricted single-particle space suggests the superiority of the present approach.
Gamow-Teller and M1 strengths in closed-shell nuclei
1985, Nuclear Physics, Section A
We study the transition strengths induced by the operators σ, σ · τ, l · τ and their combinations in the closed-shell nuclei ¹⁶O and ⁴⁰Ca. The total, inverse energy-weighted and energy-weighted strengths are calculated in perturbation theory. The results are discussed in connection with the available data. A large amount of Gamow-Teller and M1 strength is predicted at high excitation energies.
Microscopic and macroscopic aspects of 135 MeV proton scattering from 16O
1984, Nuclear Physics, Section A
Differential cross sections have been measured for the scattering of 135 MeV protons from ¹⁶O and data from the transitions to 13 states (up to 19.5 MeV excitation) have been analysed using microscopic and macroscopic nuclear reaction models. Extensive collective model calculations have been made of the transitions to all natural-parity states. The deformation parameters for the 4p4h rotational band are in good agreement with theoretical models. The inelastic scattering data from the excitation of the negative-parity states have also been analysed in the distorted-wave approximation using microscopic (shell and RPA) models of nuclear structure and with density-dependent two-nucleon t-matrices. For positive-parity states, we report the first shell-model calculation using the complete 2ħω basis space and find that the triplet of 2p2h states (4⁺, 2⁺, 0⁺) around 11 MeV excitation is quite well described by this model, as may be a 1⁺ state which is observed for the first time by proton scattering from ¹⁶O.
Nuclear magnetic properties and gamow-teller transitions
1984, Progress in Particle and Nuclear Physics
High-resolution (e, e') study of isovector M1 and M2 transitions in the oxygen isotopes. (I). 16O
1983, Nuclear Physics, Section A
The M1 and M2 transition strength distribution for ¹⁶O in the excitation energy range from 16 to 20 MeV has been measured in a high-resolution electron scattering experiment. The M1 strength is concentrated in three sharp states at E_x = 16.22, 17.14 and 18.79 MeV (± 0.01 MeV) with B(M1, k)↑ = 0.20 ± 0.02, 0.32 ± 0.03 and 0.13 ± 0.03 μ_N², respectively. An additional strength of 0.35 ± 0.09 μ_N², distributed over eight weakly excited states with excitation energies E_x = 17.4 to 18.0 MeV, brings the total measured M1 strength to B(M1, k)↑ = 1.0 ± 0.1 μ_N². The experimental M2 strength is distributed over states at E_x = 16.82, 17.78, 18.50 and 19.0 MeV (± 0.01 MeV) with B(M2, k)↑ = 19 ± 2, 13 ± 2, 59 ± 7 and 341 ± 51 μ_N² · fm², respectively. Electric transitions were also measured to states at E_x = 16.45 MeV (2⁺, E2), 17.30 MeV (1⁺, E1) and 18.20 MeV (2⁺, E2). Calculations were performed using the modified surface delta interaction in a 2p-2h shell model for the M1 transitions and the random phase approximation for the M2 transitions. The results show the sensitivity of the M1 strength as a measure of ground-state correlations and compare well with results from the ¹⁵N( $p$ , γ) reaction.

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^☆: Work partially supported by the U.S. Department of Energy.

¹: Permanent address: Department of Physics, Faculty of Science, University of Tokyo, Japan.

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Physics Letters B

Abstract

References (11)

Phys. Lett.

Phys. Lett.

Nucl. Phys.

Nucl. Phys.

Cited by (18)

Sum rules and giant resonances in nuclei

Nuclear structure of <sup>16</sup>O in a mean-field boson approach

Gamow-Teller and M1 strengths in closed-shell nuclei

Microscopic and macroscopic aspects of 135 MeV proton scattering from <sup>16</sup>O

Nuclear magnetic properties and gamow-teller transitions

High-resolution (e, e') study of isovector M1 and M2 transitions in the oxygen isotopes. (I). <sup>16</sup>O

Magnetic dipole strength in 16O☆

Abstract

Phys. Lett.

Phys. Lett.

Nucl. Phys.

Nucl. Phys.

Magnetic dipole strength in ¹⁶O☆