8Be DIRECT TRANSFER IN α+12C INELASTIC SCATTERING AND SIGNATURES OF THE ALPHA PARTICLE CONDENSATION IN THE NEAR-3α THRESHOLD STATES OF 12C

2011 ◽  
Vol 20 (04) ◽  
pp. 966-970 ◽  
Author(s):  
T. L. BELYAEVA ◽  
A. S. DEMYANOVA ◽  
A. A. OGLOBLIN ◽  
S. A. GONCHAROV
Keyword(s):  
Ground State ◽  
Orbital Motion ◽  
Direct Transfer ◽  
Hoyle State ◽  
Model Calculations ◽  
Relative Angular Momentum ◽  
Cluster Configuration ◽  
Reaction Channels ◽  
Condensed Structure ◽  
Coupled Reaction

The coupled reaction channels model calculations of the direct 8 Be transfer in the α+12 C elastic and inelastic (to the 7.65 MeV [Formula: see text] and the 9.65 MeV [Formula: see text] states) scattering have been performed. It is shown that the cluster configuration with zero relative angular momentum dominates in [Formula: see text] state being 4.4 times larger than that in the ground state. In the [Formula: see text] state, a dominance of the p-orbital motion is found. The condensed properties are confirmed in the Hoyle state. The 3α exotic, but hardly a condensed structure of the [Formula: see text] state is found.

scholarly journals Wigner SU(4) symmetry, clustering, and the spectrum of $$^{12}$$C

2021 ◽  
Vol 57 (9) ◽  
Author(s):  
Shihang Shen ◽  
Timo A. Lähde ◽  
Dean Lee ◽  
Ulf-G. Meißner
Keyword(s):  
Excited States ◽  
Ground State ◽  
Nucleon Nucleon ◽  
Irreducible Representations ◽  
Spin Orbit ◽  
Hoyle State ◽  
Nucleon Interaction ◽  
Model Calculations ◽  
Nucleon Nucleon Interaction ◽  
Spin Orbit Interactions

AbstractWe present lattice calculations of the low-lying spectrum of $$^{12}$$ 12 C using a simple nucleon–nucleon interaction that is independent of spin and isospin and therefore invariant under Wigner’s SU(4) symmetry. We find strong signals for all excited states up to $$\sim 15$$ ∼ 15  MeV above the ground state, and explore the structure of each state using a large variety of $$\alpha $$ α cluster and harmonic oscillator trial states, projected onto given irreducible representations of the cubic group. We are able to verify earlier findings for the $$\alpha $$ α clustering in the Hoyle state and the second $$2^+$$ 2 + state of $$^{12}$$ 12 C. The success of these calculations to describe the full low-lying energy spectrum using spin-independent interactions suggest that either the spin-orbit interactions are somewhat weak in the $$^{12}$$ 12 C system, or the effects of $$\alpha $$ α clustering are diminishing their influence. This is in agreement with previous findings from ab initio shell model calculations.

Spin-orbit splittings in 13C and 13N with the nature of the Hoyle state in 12C

2006 ◽  
Vol 21 (31n33) ◽  
pp. 2373-2382 ◽  
Author(s):  
Taiichi YAMADA ◽  
Hisashi HORIUCHI ◽  
Peter SCHUCK
Keyword(s):  
Ground State ◽  
Positive Parity ◽  
Spin Orbit ◽  
Hoyle State ◽  
Valence Nucleon

The spin-orbit splittings of 13 C and 13 N corresponding to the ground state and second 0+ state (Hoyle state) in 12 C are investigated within a 12 C +N model. The agreement of the calculated results with experiments suggests that the [Formula: see text] and [Formula: see text] states around Ex = 9 ~ 10 MeV in 13 C and 13 N can be interpreted as the spin-orbit partner with the [Formula: see text] configuration. We also discuss the positive parity states (including [Formula: see text]) of 13 C and 13 N around the [Formula: see text] threshold, indicating to have the configuration of the Hoyle state in 12 C plus a valence nucleon in sd shell.

Coupled reaction channels effects in the elastic scattering ofS32,36+58,64Ni

1990 ◽  
Vol 41 (3) ◽  
pp. 1018-1030 ◽  
Author(s):  
A. M. Stefanini ◽  
A. Tivelli ◽  
G. Montagnoli ◽  
D. R. Napoli ◽  
D. Bonamini ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Reaction Channels ◽  
Coupled Reaction

CHAMELEON GROUND STATE AND EXCITED STATES OF EDT-TTF-IM-F4TCNQ RADICAL DYAD IN DIFFERENT ENVIRONMENTS

2012 ◽  
Vol 11 (03) ◽  
pp. 505-525 ◽  
Author(s):  
YUHUA ZHOU ◽  
KAI TAN ◽  
XIN LU
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Excited States ◽  
Ground State ◽  
Density Functional ◽  
Solvent Polarity ◽  
Functional Study ◽  
Polar Solvents ◽  
Model Calculations ◽  
A Charge

We have performed a systematic density functional study on the ground-state electronic structure and excited states of a representative D-σ-A dyad, i.e. EDT-TTF-Im-F4TCNQ π-radical, in vacuo and in different conventional solvents (toluene, THF, DMF and DMSO) by using some popular hybrid density functionals (B3LYP, M05, M05-2X, PBE0 and BMK). It has been shown that the M05 and B3LYP functionals perform the best in predicting the intramolecular charge-transfer (ICT) pertaining to both the ground state and excited states of the dyad. The amphoteric dyad is liable to solvent-promoted ICT from its EDT-TTF-Im donor (D) to F4TCNQ acceptor (A), adopting a charge-unseparated ground state D-A• in vacuo, a partially zwitterionic ground state [D-A]• in nonpolar toluene solvent, and a fully zwitterionic ground state D•+-A- in such polar solvents as THF, DMF and DMSO. Owing to its solvent-dependent chameleon ground state, excited states of the dyad in solvents also exhibit remarkable dependence on solvent polarity, as revealed by TDDFT calculations. Furthermore, cluster model calculations revealed that intermolecular charge-transfer readily occurs between the dyads, accounting for the observed zwitterionic charge state in solid state and solid-state semiconductivity.

scholarly journals ELASTIC AND INELASTIC ALPHA TRANSFER IN THE 16O+12C SCATTERING

2021 ◽  
Vol 31 (4) ◽  
Author(s):  
Phuc Hoang Nguyen ◽  
Phuc Tri Toan Nguyen ◽  
Khoa Tien Dao
Keyword(s):  
Cross Section ◽  
Heavy Ion ◽  
Scattering Cross Section ◽  
Transition Strength ◽  
Valence Nucleon ◽  
The Core ◽  
Scattering Cross ◽  
Oscillatory Pattern ◽  
Reaction Channels ◽  
Coupled Reaction

The elastic scattering cross section measured at energies $E\lesssim 10$ MeV/nucleon for some light heavy-ion systems having two identical cores like \oc exhibits an enhanced oscillatory pattern at the backward angles. Such a pattern is known to be due to the transfer of the valence nucleon or cluster between the two identical cores. In particular, the elastic $\alpha$ transfer has been shown to originate directly from the core-exchange symmetry in the elastic \oc scattering. Given the strong transition strength of the $2^+_1$ state of $^{12}$C and its large overlap with the $^{16}$O ground state, it is natural to expect a similar $\alpha$ transfer process (or inelastic $\alpha$ transfer) to take place in the inelastic \oc scattering. The present work provides a realistic coupled channel description of the $\alpha$ transfer in the inelastic \oc scattering at low energies. Based on the results of the 4 coupled reaction-channels calculation, we show a significant contribution of the $\alpha$ transfer to the inelastic \oc scattering cross section at the backward angles. These results suggest that the explicit coupling to the $\alpha$ transfer channels is crucial in the studies of the elastic and inelastic scattering of a nucleus-nucleus system with the core-exchange symmetry.\Keywords{optical potential, coupled reaction channels, inelastic $\alpha$ transfer

scholarly journals Elastic and inelastic scattering of 15N ions by 13C nuclei at energy 84 MeV

2021 ◽  
Vol 22 (1) ◽  
pp. 10-18
Author(s):  
A.T. Rudchik ◽  
◽  
A.A. Rudchik ◽  
O.E. Kutsyk ◽  
K. Rusek ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Inelastic Scattering ◽  
Transfer Reactions ◽  
Coupling Scheme ◽  
Elastic And Inelastic Scattering ◽  
Deformation Parameters ◽  
Cluster Transfer ◽  
Reaction Channels ◽  
Potential Parameters ◽  
Coupled Reaction

New experimental data of the 15N + 13C elastic and inelastic scattering were obtained at the energy Elab(15N) = 84 MeV. The data were analyzed within the coupled-reaction-channels method. The elastic and inelastic scattering of nuclei 15N + 13С as well as the more important nucleon and cluster transfer reactions were included in the channels-coupling scheme. The WS potential parameters for the 15N + 13С nuclei interactions in ground and excited states as well as deformation parameters of these nuclei were deduced. The contributions of one- and two-step transfers in the 15N + 13C elastic and inelastic scattering were estimated. The results of the 15N + 13С elastic scattering at the energy Elab(15N) = 84 MeV, obtained in this work, were compared with that of the 15N + 12С elastic scattering at the energy Elab(15N) = 81 MeV.

Shell model description of the 0+ and 0− excited states in sd shell nuclei

2018 ◽  
Vol 96 (7) ◽  
pp. 774-778 ◽  
Author(s):  
M. Bouhelal ◽  
N. Saidane ◽  
S. Belaid ◽  
F. Haas
Keyword(s):  
Shell Model ◽  
Excited States ◽  
Ground State ◽  
Model Description ◽  
Excitation Energies ◽  
Model Calculations ◽  
The Future

The purpose of this work is to describe, in light of shell model calculations using the PSDPF interaction, the particular states with J = 0 in sd shell nuclei. These states are difficult to observe. It is well known that the ground state in even–even nuclei has Jπ = 0+ and therefore we are interested in describing their first excited [Formula: see text] states. We have also studied the first and second excited 0− states in all sd nuclei. The experimental and theoretical excitation energies of these states were confronted. This study allowed us to make predictions of the existence of [Formula: see text] and (or) [Formula: see text] states in nuclei, which do not possess these states, or to have an idea of their excitation energies for possible experiments in the future.

SHELL MODEL CALCULATIONS OF 3T, 5He AND 6Li NUCLEI

2002 ◽  
Vol 11 (01) ◽  
pp. 67-70
Author(s):  
NAZIH EL-NOHY
Keyword(s):  
Binding Energy ◽  
Shell Model ◽  
Root Mean Square ◽  
Long Range ◽  
Ground State ◽  
Radial Dependence ◽  
Spin Orbit ◽  
Mean Square ◽  
Model Calculations ◽  
Short Range Repulsion

The bases of the translation invariant shell model are used to construct the ground-state wave functions of 3 T , 5 He and 6 Li . For 3 T the bases used correspond to the number of quanta of excitation N up to ten. For 5 He and 6 Li the bases used correspond to the number of quanta of excitation N up to six. The model is applied to calculate the binding energy and the root mean square radius for 3 T , 5 He and 6 Li nuclei. The residual interactions used consist of central, tensor, spin-orbit and quadratic spin-orbit terms with Gaussian radial dependence. The parameters of these interactions are chosen in such away that they represent the long range attraction and the short range repulsion of nucleon interactions. It was found that this potential is more suitable for calculating the characteristics of these nuclei, and better than other potentials, such as our previous potentials which were represented by the parameters of long range attraction forces only. For 3T we obtained good agreement between calculated and experimental values of both the ground state binding energy and the root mean square radius. For 5 He and 6 Li nuclei we obtained an acceptable improvement with these calculations over other potentials.

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