ISSN:0094-243X    

DOI:10.1063/1.31437

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The Time‐Dependent Hartree‐Fock method is used to produce time dependent graphical representations of the density contours of the binary cluster in the reactions14N(112 MeV) +12C,16O(384 MeV) +16O, and20Ne(164 MeV) +58Ni. Alpha clustering and multipole shape vibrations are seen. Predictions for d&sgr;/d&OHgr;, d&sgr;/dZf, and d2&sgr; (Ef)d&OHgr;dEf*Zfare obtained in the case of14N +12C and found to agree well with available experimental data. It is concluded that cluster dynamics play an essential role in heavy‐ion reactions.

ISSN:0094-243X    

DOI:10.1063/1.31447

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The presence of quartets — the more physical term for SU4 structures — is demonstrated for nuclei throughout the table. A very strong indication for quartets is the validity of a mass formula based on SU4. This formula achieves with fewer parameters the classical liquid drop terms then turns out to have at least as good a fit to the data as the usual Weizsa¨cker formula. The physical reasons for quartetting are presented; possible forms of the quartet correlations, different for different regions of the Table, are discussed.

ISSN:0094-243X    

DOI:10.1063/1.31456

出版商:AIP    

年代:1978

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.31558

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A selected review is given of comparisons of experimental data for low‐mass nuclear systems with results of calculations using microscopic cluster models. Stress is on the mass‐4, ‐7, and ‐8 systems. Topics include influence of components of the nucleon‐nucleon force, some consequences of the Pauli principle, effects of the Coulomb‐exchange interaction, specific distortion, absorption in elastic scattering, and future needs and directions. Some as yet unpublished results are presented.

ISSN:0094-243X    

DOI:10.1063/1.31588

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Four mainstream theoretical descriptions of nuclear matter flow are measured against six physical features of nuclei and nuclear heavy‐ion collisions. Conventional (one single‐determinantal wave function) Time‐Dependent Hartree‐Fock Theory emerges favorably from the comparison, but fares poorly as a phenomenology. A completely restructured theory, the T.D.−S−H.F., involving many single‐determinantal wave functions is proposed by analogy with S‐matrix reaction theory. It leads one to place the physical interpretation of the reactions upon time averages of asymptotic channel states of ’’TDHF Droplets,’’ comprising the translations and periodic TDHF vibrations of isolated integer‐nucleon subsystems. In its most naive form (based on small amplitude properties) the theory would consistently describe only the kinematic behavior of ’’classical’’ intrinsically dissipative TDHF droplets. But if the periodic solutions of TDHF were to occur only at isolated energies and amplitudes then the theory would describe quantized TDHF droplets with (time‐averaged) orthogonal channels, in which periodic solutions play the role of eigenstates in close analogy with the Schro¨dinger theory.

ISSN:0094-243X    

DOI:10.1063/1.31431

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A band crossing model is shown to be successful in the explanation and the prediction of resonance phenomena in heavy ion scatterings, which is exemplified in the12C+16O system. Oscillations observed in fusion cross sections, for example in the12C +12C system, are shown not to be resonances or a reflection of resonances, but to be signals of strong absorption suffered by particular partial waves. Molecular resonances, possible existences of which are predicted by the band crossing model, are investigated whether they survive or are smeared out under strong absorption. The absorption is treated by smooth‐cut‐off model. The intermediate structure observed in the elastic excitation function of the12C +12C system is reproduced excellently well and shown to be a direct reflection of existence of molecular resonances.

ISSN:0094-243X    

DOI:10.1063/1.31432

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Recent theoretical studies of the structure of light nuclei by the multi‐cluster model approach are reviewed. It is emphasized that the treatment based on the microscopic theory is very important, especially the proper treatment of the Pauli exclusion principle in describing two‐cluster interaction process. Various calculations on the 3&agr; problem of12C are compared each other with the stress on the reproduction of the coexistence phenomena of the shell and cluster structures. Many recent multi‐cluster approaches to the systems other than12C are discussed, showing a hopeful scope of this approach together with the future problems to be solved.

ISSN:0094-243X    

DOI:10.1063/1.31433

出版商:AIP    

年代:1978

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.31434

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Recent observations of the electrofission of light nuclei are summarized together with available data on the time‐reversed reaction, heavy ion radiative capture.

ISSN:0094-243X    

DOI:10.1063/1.31435

出版商:AIP    

年代:1978

数据来源: AIP