scholarly journals Enhanced monopole and dipole transitions in nuclei induced by α cluster structures

2019 ◽  
Vol 223 ◽  
pp. 01026
Author(s):  
Makoto Ito ◽  
Makoto Nakao ◽  
Tomoyuki Okuno ◽  
Syuuichiro Ebata
Keyword(s):  
Excitation Energy ◽  
Theoretical Calculation ◽  
Relative Motion ◽  
Residual Nucleus ◽  
Mean Field ◽  
Discrete Distribution ◽  
Cluster Models ◽  
Transition Strength ◽  
Single Nucleon

Enhancement of the monopole and dipole transitions in the low-lying state is discussed on the basis of the microscopic and macroscopic α cluster models. Theoretical calculation clearly demonstrates that the strength of the monopole and dipole transitions are strongly enhanced by the excitation in the relative motion of the α cluster and the residual nucleus. The transition strength induced by the α excitation appears as the discrete distribution, and its excitation energy is much lower than the excitation energy of the single nucleon excitation, which is expected from the naive mean field picture.

A study of the nuclear disintegrations produced by 950 MeV protons

1955 ◽  
Vol 231 (1186) ◽  
pp. 368-378 ◽  
Keyword(s):  
Simple Model ◽  
Excitation Energy ◽  
Residual Nucleus ◽  
Parent Nucleus ◽  
Heavy Nuclei ◽  
Substantial Fraction ◽  
Photographic Emulsions ◽  
Mev Protons

Nuclear disintegrations produced in the heavy nuclei of Ilford G 5 photographic emulsions by 950 MeV protons have been analyzed in detail. The characteristics of the disintegrations observed can be explained in terms of a simple model which assumes that a substantial fraction of the π mesons created is reabsorbed in the parent nucleus and that the energy of these mesons contributes mainly to the excitation energy of the residual nucleus.

scholarly journals RELATIVE MOTION CORRECTION TO FISSION BARRIERS

2008 ◽  
Vol 17 (01) ◽  
pp. 151-159 ◽  
Author(s):  
J. SKALSKI
Keyword(s):  
Relative Motion ◽  
Cluster Model ◽  
Motion Correction ◽  
Mean Field Theory ◽  
Mean Field ◽  
Ternary Fission ◽  
Skyrme Interaction ◽  
Hartree Fock ◽  
Fission Barriers ◽  
The Mean

We discuss the effect of kinetic energy of the relative motion becoming spurious for separate fragments on the selfconsistent mean-field fission barriers. The treatment of the relative motion in the cluster model is contrasted with the necessity of a simpler and approximate approach in the mean-field theory. A scheme of the energy correction to the Hartree-Fock is proposed. The results obtained with the effective Skyrme interaction SLy 6 show that the correction, previously estimated as ~ 8 MeV in A = 70 - 100 nuclei, amounts to 4 MeV in the medium heavy nucleus 198 Hg and to null in 238 U . However, the corrected barrier implies a shorter fission half-life of the latter nucleus. The same effect is expected to lower barriers for multipartition (i.e. ternary fission, etc) and make hyperdeformed minima less stable.

scholarly journals Residual nucleus excitation energy in (e, e'p): reaction

2004 ◽  
Vol 34 (3a) ◽  
pp. 753-755
Author(s):  
V. P. Likhachev ◽  
J. D. T. Arruda-Neto ◽  
M.T.F. da Cruz ◽  
H. Dias ◽  
S.B. Duarte ◽  
...  
Keyword(s):  
Excitation Energy ◽  
Residual Nucleus

Nonstatistical fluctuations of target fragments emitted in high-energy nucleus–nucleus collisions

2002 ◽  
Vol 80 (2) ◽  
pp. 119-128
Author(s):  
N N Abd-Allah
Keyword(s):  
Excitation Energy ◽  
Impact Parameter ◽  
Target Nucleus ◽  
Incident Energy ◽  
Nuclear Emulsion ◽  
Residual Nucleus ◽  
High Energy ◽  
Critical Value ◽  
Nucleus Interaction ◽  
The Impact

Analysis of target-fragmented "black" particles in nuclear emulsion from high-energy relativistic interactions initiated by 28Si at 4.5 A GeV/c is investigated. The number of slowly emitted particles from the struck target nucleus is considered as a measure of the degree of excitation of the residual nucleus. This number shows a constant critical value, with the degree of the impact parameter or the degree of excitation. The target evaporation particles of nucleus–nucleus interaction reveal the existence of nonstatistical fluctuations in the azimuthal plane of the interaction. The asymmetry or nonstatistical fluctuations, while found to be independent of projectile mass or incident energy, are dependent on the excitation energy of the target nucleus. A multiparticle correlation is observed between created particles as well as target fragments. This assumes production of clusters. These clusters seem to be formed during the decoloring process. PACS No.: 25.70Mn

scholarly journals Isoscalar giant monopole resonance for drip-line and super heavy nuclei in the framework of relativistic mean field formalism with scaling calculation

Open Physics ◽  
2014 ◽  
Vol 12 (8) ◽  
Author(s):  
Subrata Biswal ◽  
Suresh Patra
Keyword(s):  
Excitation Energy ◽  
Mean Field Theory ◽  
Mean Field ◽  
Magic Numbers ◽  
Heavy Nuclei ◽  
Isotopic Chain ◽  
Excitation Energies ◽  
Relativistic Mean Field ◽  
Giant Monopole Resonance ◽  
Super Heavy Nuclei

AbstractWe study the isoscalar giant monopole resonance for drip-lines and super heavy nuclei in the framework of relativistic mean field theory with a scaling approach. The well known extended Thomas-Fermi approximation in the nonlinear σ-ω model is used to estimate the giant monopole excitation energy for some selected light spherical nuclei starting from the region of proton to neutron drip-lines. The application is extended to the super heavy region for Z=114 and 120, which are predicted by several models as the next proton magic numbers beyond Z=82. We compared the excitation energy obtained by four successful force parameters NL1, NL3, NL3*, and FSUGold. The monopole energy decreases toward the proton and neutron drip-lines in an isotopic chain for lighter mass nuclei, in contrast to a monotonic decrease for super heavy isotopes. The maximum and minimum monopole excitation energies are obtained for nuclei with minimum and maximum isospin in an isotopic chain, respectively.

A study of the 34S(α,γ)38Ar reaction

1979 ◽  
Vol 57 (6) ◽  
pp. 781-792 ◽  
Author(s):  
K. N. Sinha ◽  
A. G. Hwang ◽  
H.-B. Mak ◽  
H. C. Evans
Keyword(s):  
Excitation Energy ◽  
Energy Range ◽  
Decay Scheme ◽  
Transition Strength ◽  
Mixing Ratio

The reaction 34S(α,γ)38Ar has been investigated in the energy range Eα = 2.0–3.5 MeV. Eighteen resonance levels were found, nine of which have not been previously reported; six of the new levels have J > 1. The excitation energy, Jπ, decay scheme, mixing ratio, and transition strength for decays from the resonances were deduced.

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