QUARTETTING IN ATTRACTIVE FERMI-SYSTEMS AND ALPHA PARTICLE CONDENSATION IN NUCLEAR SYSTEMS

2007 ◽  
Vol 21 (13n14) ◽  
pp. 2420-2428
Author(s):  
P. SCHUCK ◽  
Y. FUNAKI ◽  
H. HORIUCHI ◽  
G. RÖPKE ◽  
A. TOHSAKI ◽  
...  
Keyword(s):  
Transition Probability ◽  
Adjustable Parameter ◽  
Low Density ◽  
Hoyle State ◽  
Fermi Systems ◽  
Nuclear Systems ◽  
Physical Quantities ◽  
Two Parameter ◽  
Parameter Wave ◽  
Α Particles

The famous Hoyle state (02+ at 7.654 MeV in 12 C ) is identified as being an almost ideal condensate of three α-particles, hold together only by the Coulomb barrier. It, therefore, has a 8 Be -α structure of low density. Transition probability and inelastic form factor together with position and other physical quantities are correctly reproduced without any adjustable parameter from our two parameter wave function of α-particle condensate type. The possibility of the existence of α-particle condensed states in heavier nα nuclei is also discussed.

ALPHA CLUSTERING AND CONDENSATION IN NUCLEI

2011 ◽  
Vol 20 (04) ◽  
pp. 874-879 ◽  
Author(s):  
Y. FUNAKI ◽  
T. YAMADA ◽  
H. HORIUCHI ◽  
G. RÖPKE ◽  
P. SCHUCK ◽  
...  
Keyword(s):  
Orthogonality Condition ◽  
Low Density ◽  
Breakup Threshold ◽  
Condition Model ◽  
Strong Enhancement ◽  
Alpha Clustering ◽  
Α Particles

Low density states near the 3α and 4α breakup threshold in 12 C and 16 O , respectively, are discussed in terms of the α-particle condensation. Calculations are performed in OCM (Orthogonality Condition Model) and THSR (Tohsaki-Horiuchi-Schuck-Röpke) approaches. The [Formula: see text] state in 12 C and the [Formula: see text] state in 16 O are shown to have dilute density structures and give strong enhancement of the occupation of the S-state c.o.m. orbital of the α-particles. The possibility of the existence of α-particle condensed states in heavier nα nuclei is also discussed.

scholarly journals Superconductivity in Repulsive Fermi-Systems at Low Density

2013 ◽  
Vol 26 (9) ◽  
pp. 2809-2815 ◽  
Author(s):  
M. Y. Kagan ◽  
D. V. Efremov ◽  
M. S. Mar’enko ◽  
V. V. Val’kov
Keyword(s):  
Low Density ◽  
Fermi Systems

Kohn-Luttinger effect and anomalous pairing in repulsive Fermi-systems at low density (Review Article)

2012 ◽  
Vol 38 (9) ◽  
pp. 874-879
Author(s):  
M. Yu. Kagan ◽  
D. V. Efremov ◽  
M. S. Mar'enko ◽  
V. V. Val'kov
Keyword(s):  
Review Article ◽  
Low Density ◽  
Fermi Systems

scholarly journals Identification of highly deformed even–even nuclei in the neutron- and proton-rich regions of the nuclear chart from the B(E2)↑ and E2 predictions in the generalized differential equation model

2015 ◽  
Vol 24 (12) ◽  
pp. 1550091
Author(s):  
R. C. Nayak ◽  
S. Pattnaik
Keyword(s):  
Differential Equation ◽  
Large Deformations ◽  
Transition Probability ◽  
Electric Quadrupole ◽  
Mass Region ◽  
Equation Model ◽  
Generalized Differential Equation ◽  
Predicted Values ◽  
Generalized Differential ◽  
Physical Quantities

We identify here the possible occurrence of large deformations in the neutron- and proton-rich ([Formula: see text]-rich and [Formula: see text]-rich) regions of the nuclear chart from extensive predictions of the values of the reduced quadrupole transition probability [Formula: see text] for the transition from the ground state to the first [Formula: see text] state and the corresponding excitation energy [Formula: see text] of even–even nuclei in the recently developed generalized differential equation (GDE) model exclusively meant for these physical quantities. This is made possible from our analysis of the predicted values of these two physical quantities and the corresponding deformation parameters derived from them such as the quadrupole deformation [Formula: see text], the ratio of [Formula: see text] to the Weisskopf single-particle [Formula: see text] and the intrinsic electric quadrupole moment [Formula: see text], calculated for a large number of both known as well as hitherto unknown even–even isotopes of oxygen to fermium (0 to FM; [Formula: see text]–100). Our critical analysis of the resulting data convincingly support possible existence of large collectivity for the nuclides [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text], whose values of [Formula: see text] are found to exceed 0.3 and even 0.4 in some cases. Our findings of large deformations in the exotic [Formula: see text]-rich regions support the existence of another “island of inversion” in the heavy-mass region possibly caused by breaking of the [Formula: see text] subshell closure.

PRESENT STATUS OF ALPHA-PARTICLE CONDENSATE STATES IN SELF-CONJUGATE 4n NUCLEI

2008 ◽  
Vol 17 (10) ◽  
pp. 2087-2095 ◽  
Author(s):  
Y. FUNAKI ◽  
T. YAMADA ◽  
H. HORIUCHI ◽  
G. RÖPKE ◽  
P. SCHUCK ◽  
...  
Keyword(s):  
Alpha Particle ◽  
Present Status ◽  
The State ◽  
Orthogonality Condition ◽  
Low Density ◽  
Breakup Threshold ◽  
Large Component ◽  
Condition Model ◽  
Strong Enhancement ◽  
Α Particles

Low density states near the 3α and 4α breakup threshold in 12 C and 16 O , respectively, are discussed in terms of the α-particle condensation. Calculations are performed in OCM (Orthogonality Condition Model) and THSR (Tohsaki-Horiuchi-Schuck-Röpke) approaches. The [Formula: see text] state in 12 C and the [Formula: see text] state in 16 C are shown to have dilute density structures and give strong enhancement of the occupation of the S-state c.o.m. orbital of the α-particles. The [Formula: see text] state in 16 C has a large component of [Formula: see text] configuration, which is another reliable evidence of the state to be of 4α condensate nature. The possibility of the existence of α-particle condensed states in heavier nα nuclei is also discussed.

scholarly journals MANY BODY THEORY FOR QUARTETS, TRIONS, AND PAIRS IN LOW DENSITY MULTI-COMPONENT FERMI-SYSTEMS

2009 ◽  
Vol 24 (11) ◽  
pp. 2027-2034 ◽  
Author(s):  
P. SCHUCK ◽  
T. SOGO ◽  
G. RÖPKE
Keyword(s):  
Low Density ◽  
Many Body ◽  
Fermi Systems ◽  
Many Body Theory ◽  
Body Theory

A selfconsistent many body approach for the description of gases with quartets, trions, and pairs is presented. Applications to 3D Fermi systems at low density are discussed.

scholarly journals Four α-particles as a final state of 16O* Quasi Projectile decay

2019 ◽  
Vol 223 ◽  
pp. 01036
Author(s):  
Maria Vittoria Managlia ◽  
Mauro Bruno ◽  
Michela D’Agostino ◽  
Luca Morelli ◽  
Giorgio Baiocco ◽  
...  
Keyword(s):  
Statistical Model ◽  
Branching Ratios ◽  
Event Analysis ◽  
Hoyle State ◽  
Final State ◽  
Decay Channels ◽  
Transmission Coefficients ◽  
The One ◽  
Negligible Contribution ◽  
Α Particles

Four α-particles as a final state of 16O* quasi-projectile decayproduced in peripheral 16O+12C reactions at 130 MeV is thoroughly studied. The differentdecay channels leading to the four α-particles final state are reconstructed by carrying out an event-by-event analysis of α correlations in the population of intermediate 8Be and 12C. Although small, a non negligible contribution due to 8Begs evaporation is found.A comparison between predictions of an accurate Hauser-Feshbach decay code and branching ratios of the different decay channels is performed. Significant deviations are observed, among these the Hoyle state population which is considerably lower than the one predicted according to the statistical model, thus suggesting possible structure effects in the Coulomb barrier and/or in the transmission coefficients.

The Influence of the Extreme Fluences of 8 MeV Protons on Characteristics of SiC Nuclear Detectors Produced by Al Implantation

2007 ◽  
Vol 556-557 ◽  
pp. 961-964 ◽  
Author(s):  
Alexander M. Ivanov ◽  
Nikita B. Strokan ◽  
Alexander A. Lebedev ◽  
Vitalii V. Kozlovski
Keyword(s):  
Experimental Data ◽  
Collection Efficiency ◽  
Charge Collection ◽  
Carrier Localization ◽  
Charge Collection Efficiency ◽  
Radiation Induced ◽  
Nuclear Detectors ◽  
Two Parameter ◽  
Mev Protons ◽  
Α Particles

The charge collection efficiency (ССЕ) of SiC-detectors preliminarily irradiated with 8 MeV protons at a fluence of 1014 cm-2 has been studied. Nuclear spectrometric techniques with 5.4 MeV α-particles were employed to test the detectors. The concentration of primarily created defects was estimated to be 4×1016 cm-3. A strong compensation of SiC was observed, which allowed connection of the structure in the forward mode. The experimental data obtained were processed using a simple two-parameter model of signal formation. The model makes it possible to separate the contributions of electrons and holes to the ССЕ. An additional irradiation at a fluence of 2×1014 cm-2 reduced the ССЕ value by a factor of 2 and gave rise to polarization. The latter indicates that radiation-induced centers are not only actively involved in carrier localization (with a decrease in the lifetime), but also in transformation of the electric field within the detector.

scholarly journals Dependence of Information Entropy of Uniform Fermi Systems on Correlations and Thermal Effects

2020 ◽  
Vol 13 ◽  
pp. 173
Author(s):  
Ch. C. Moustakidis ◽  
S. E. Massen
Keyword(s):  
Kinetic Energy ◽  
Information Entropy ◽  
Thermal Effects ◽  
Electron Gas ◽  
Fermi System ◽  
Temperature Limit ◽  
Fermi Systems ◽  
The Mean ◽  
Two Parameter ◽  
Mean Kinetic Energy

The influence of correlations of uniform Fermi systems (nuclear matter, electron gas and liquid 3He) on Shannon's information entropy, S, is studied. It is found that, for three different Fermi systems with different particle interactions, the correlated part of S (Soor) depends on the correlation parameter of the systems or on the discontinuity gap of the momentum distribution through two parameter expressions. The values of the parameters characterize the strength of the correlations. A two parameter expression also holds between Scor and the mean kinetic energy (K) of the Fermi system. The study of thermal effects on the uncorrelated electron gas leads to a relation between the thermal part of S (Sthermai) and the fundamental quantities of temperature, thermodynamical entropy and the mean kinetic energy. It is found that, in the case of low temperature limit, the expression connecting Sthermai with Κ is the same to the one which connects Scor with K. Thus, regardless of the reason (correlations or thermal) that changes K, S takes almost the same value.

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