Core excitation in one neutron halo systems

doi:10.1016/0375-9474(95)00398-3

Nuclear Physics A

Volume 596, Issue 2, 8 January 1996, Pages 171-186

https://doi.org/10.1016/0375-9474(95)00398-3 Get rights and content

Abstract

Coupled channel calculations are performed for one neutron halo nuclei using a rotational model for the core structure. A deformed Woods-Saxon potential is used for the neutron-core interaction, where the deformation parameter is estimated using the quadrupole moment of the core and the charge to mass deformation ratio given by shell model calculations.

Mean square radii and B(E1) transitions from the first excited state to the ground state in ¹¹Be are presented and good agreement with experiment is found. The same calculations were performed for ¹³C but the agreement with experiment was not as good. Phase shifts for low energy neutrons on ¹⁰Be and ¹²C are calculated and we determine positions and widths of resonances. Predictions for the continuum only partly agree with the experimental spectrum. We also calculate the B(E1) distribution of ¹¹Be for transitions from the ground state to the continuum and these agree with recent coulomb dissociation data. Following the controversy generated by the experimental results for the ground state in ¹⁰Li, we apply our method to investigate the structure of this nucleus.

References (39)

C.A. Bertulani et al.
Phys. Reports
(1993)
I. Tanihata et al.
Phys. Lett. B
(1985)
M.J. Borge et al.
Phys. Rev. Lett. B
(1993)
T. Hoshino et al.
Nucl. Phys. A
(1990)
M.V. Zhukov et al.
Phys. Reports
(1993)
H. Sagawa et al.
Phys. Lett. B
(1993)
M. Rotenberg
Ann. Phys.
(1962)
S. Raman
At. Data Nucl. Data Tables
(1987)
F. Ajzenberg-Selove
Nucl. Phys. A
(1988)
B. Cross

E. Liatard et al.

Europhys. Lett.

(1990)

W.J. Vermeer et al.

Phys. Lett. B

(1983)

R.C. Barrett and D.F. Jackson, Nuclear Sizes and Structure (Clarendon Press, Oxford) p....

B.M. Young et al.

Phys. Rev. C

(1994)

B.A. Brown, A. Etchegoyegen, N.S. Godwin, W.E. Ormand, W.D. Rae, E.K. Warburton, J.S. Winfield and L. Zhao, The...

I. Tanihata

Nucl. Phys. A

(1991)

P.G. Hansen

Nucl. Phys. A

(1993)

D.J. Millener et al.

Phys. Rev. C

(1983)

T. Otsuka et al.

Phys. Rev. Lett.

(1993)

Cited by (149)

Two-proton emission and related phenomena
2023, Progress in Particle and Nuclear Physics
One of characteristic phenomena for nuclei beyond the proton dripline is the simultaneous emission of two protons (2p). The current status of our knowledge of this most recently observed and the least known decay mode is presented. First, different approaches to theoretical description of this process, ranging from effective approximations to advanced three-body models are overviewed. Then, after a brief survey of main experimental methods to produce 2p-emitting nuclei and techniques to study their decays, experimental findings in this research field are presented and discussed. This review covers decays of short-lived resonances and excited states of unbound nuclei as well as longer-lived, ground-state radioactive decays. In addition, more exotic decays like three- and four-proton emission are addressed. Finally, related few-body topics, like two-neutron and four-neutron radioactivity, and the problem of the tetraneutron are shortly discussed.
Simulating core excitation in breakup reactions of halo nuclei using an effective three-body force
2022, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
We extend our previous calculation of the breakup of ¹¹Be using Halo Effective Field Theory and the Dynamical Eikonal Approximation to include an effective ¹⁰Be-n-target force. The force is constructed to account for the virtual excitation of ¹⁰Be to its low-lying $2^{+}$ excited state. In the case of breakup on a ¹²C target this improves the description of the neutron-energy and angular spectra, especially in the vicinity of the ¹¹Be ${\frac{5}{2}}^{+}$ state. By fine-tuning the range parameters of the three-body force, a reasonable description of data in the region of the ${\frac{3}{2}}^{+}$ ¹¹Be state can also be obtained. This sensitivity to the three-body force's range results from the structure of the overlap integral that governs the ¹¹Be s-to-d-state transitions which it induces.
Exploring the core deformation properties of 29F halo nucleus using T- and Y-configurations
2021, Chinese Journal of Physics
²⁹F nucleus is a two-neutron halo nucleus with the core (²⁷F) + n + n three-body system. We studied the Jacobi coordinates dependant T-and Y-configurations properties due to the core deformation of this nucleus. For this deformation of the core, the separation energy (S_2n) and the root mean square (RMS) matter radius of this halo nucleus were calculated. This theoretical calculation for investigating T-and Y-configuration properties was accomplished through the MATLAB computational software. A positive core deformation was found, which indicates a prolate shaped halo nucleus. We found an excellent agreement for S_2n and 96.4% and 96% accuracies for the T- and Y-configurations respectively.
Theory of deuteron stripping and pick-up reactions for nuclear structure studies
2020, Progress in Particle and Nuclear Physics
Deuteron stripping and pick-up experiments - $(d, p)$ and $(p, d)$ - have been used for a long time to study the structure of nuclei. Today these experiments are often carried out in inverse kinematics in state-of-the-art radioactive beams facilities around the world, extending the boundaries of our knowledge of the nuclear chart. The nuclear structure information obtained from these experiments relies entirely on transfer reaction theory. We review the theory of $(d, p)$ and $(p, d)$ reactions starting from early formulations and ending with the most recent developments. In particular, we describe the recent progress made in the understanding of the three-body dynamics associated with the deuteron breakup degrees of freedom, including effects of nonlocality, and discuss the role of many-body degrees of freedom within the three-body context. We also review advances in structure model calculations of one-nucleon overlap functions — an important structure input to $(d, p)$ and $(p, d)$ reaction calculations. We emphasize the physics missing in widely-used standard approaches available to experimentalists and review ideas and efforts aimed at including this physics, formulating the crucial tasks for further development of deuteron stripping and pick-up reaction theory.
Investigating the 10 Li continuum through 9 Li(d,p) 10 Li reactions
2019, Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
The continuum structure of the unbound system ¹⁰Li, inferred from the ⁹Li ${(d, p)}^{10}$ Li transfer reaction, is reexamined. Experimental data for this reaction, measured at two different energies, are analyzed with the same reaction framework and structure models. It is shown that the seemingly different features observed in the measured excitation energy spectra can be understood as due to the different incident energy and angular range covered by the two experiments. The present results support the persistence of the $N = 7$ parity inversion beyond the neutron dripline as well as the splitting of the well-known low-lying p-wave resonance. Furthermore, they provide indirect evidence that most of the $ℓ = 2$ single-particle strength, including possible $d_{5 / 2}$ resonances, lies at relatively high excitations energies.
Breakup reactions of light and medium mass neutron drip line nuclei
2018, Progress in Particle and Nuclear Physics
The formal theories of breakup reactions are reviewed. The direct breakup mechanism that is formulated within the framework of the post-form distorted-wave Born approximation, is discussed in detail. In this theory, which requires the information about only the ground state wave function of the projectile, the fragment–target interactions are included to all orders while fragment–fragment interaction is treated only in the first order. We put special emphasis on the breakup reactions of the near neutron drip line nuclei on heavy nuclear targets, which are dominated by the pure Coulomb breakup mechanism. The applicability of this theory to describe such reactions involving both spherical as well as deformed projectiles, is demonstrated by comparing the calculations with breakup data for total, energy and angle integrated cross sections and momentum distributions of fragments emitted in such reactions. Roles played by the pure Coulomb, pure nuclear and the Coulomb–nuclear interference terms in describing the breakup observables are discussed. Postacceleration effects in the Coulomb breakup of neutron halo nuclei are elaborated. The function of the pure Coulomb breakup mechanism in the one-neutron removal reactions of the type $A (a, b γ) X$ on heavy target nuclei is underlined. The relationship between the parallel momentum distribution of the fragments and the break down of the magic numbers as the neutron drip line is approached, is highlighted.

View all citing articles on Scopus

View full text

Article preview

Nuclear Physics A

Abstract

References (39)

Phys. Reports

Phys. Lett. B

Phys. Rev. Lett. B

Nucl. Phys. A

Phys. Reports

Phys. Lett. B

Ann. Phys.

At. Data Nucl. Data Tables

Nucl. Phys. A

Europhys. Lett.

Phys. Lett. B

Phys. Rev. C

Nucl. Phys. A

Nucl. Phys. A

Phys. Rev. C

Phys. Rev. Lett.

Cited by (149)

Two-proton emission and related phenomena

Simulating core excitation in breakup reactions of halo nuclei using an effective three-body force

Exploring the core deformation properties of <sup>29</sup>F halo nucleus using T- and Y-configurations

Theory of deuteron stripping and pick-up reactions for nuclear structure studies

Investigating the <sup>10</sup> Li continuum through <sup>9</sup> Li(d,p) <sup>10</sup> Li reactions

Breakup reactions of light and medium mass neutron drip line nuclei