118 research outputs found
Novel and simple description for a smooth transition from -cluster wave functions to -coupling shell model wave functions
We propose an improved version of Antisymmetrized Quasi-Cluster Model (AQCM)
to describe a smooth transition from the -cluster wave function to the
-coupling shell model wave function and apply it to the ground state of
C. The cluster-shell transition in C is characterized in AQCM by
only two parameters: representing the distance between clusters
and the center of mass, and describing the break of
clusters. The optimal AQCM wave function for the ground state of C is an
intermediate state between the three- cluster state and the shell model
state with the subshell closure configuration. The result is
consistent with that of the Antisymmetrized Molecular Dynamics (AMD), and the
optimal AQCM wave function quantitatively agrees with the AMD one, although the
number of degrees of freedom in AQCM is significantly fewer.Comment: 11 pages, 6 figure
Gross features of the spectrum of the 36Ar nucleus
Samples of the spectrum of the 36Ar nucleus are known in different energy
windows. In addition to the ground state region (GS), the superdeformed (SD)
state is observed, too, and there is a good candidate for the hyperdeformed
(HD) one, as well. They are populated in different reactions. We intend to
describe the gross features of the spectra of different energies, deformations
and reactions in a unified way. We apply the multiconfigurational dynamical
symmetry (MUSY). The SU(3) quantum numbers of the shape isomers from previous
studies pave the way for this description. The MUSY reproduces the gross
features of the spectra to a reasonable approximation. The energy spectrum of
the three valleys (GS, SD, HD) indicates that the multiconfigurational symmetry
is valid to a good approximation, and different cluster configurations coexist
in the shape isomers.Comment: 12 pages, 5 figure
Dual breaking of symmetries in algebraic models
The general features of the dual symmetry breaking in the algebraic structure models are discussed. Dual breaking indicates here simultaneous dynamical and spontaneous breaking. Several examples are considered, including the multiconfigurational dynamical symmetry (MUSY), which is the common intersection of the shell, collective and cluster models for the multi shell problem
Atommagok egzotikus bomlásai, állapotai és szimmetriái = Exotic nuclear decays, states and symmetries
Az atommagok egzotikus bomlásait, állapotait és szimmetriáit tanulmányoztuk. Szisztematikusan feltártuk néhány könnyű és nehéz mag lehetséges fürtösödését (klaszterizációját). Ezáltal hozzájárultunk az egzotikus bomlások szerkezeti aspektusának tisztázásához. A vizsgált atommagoknak nem csak az alapállapotát, hanem a szuper- és hiperdeformált állapotait is tanulmányoztuk. A fürtösödés és az egzotikus alak (állapot) kapcsolatát egy igen általános szimmetria, az u.n. kvázidinamikai szimmetria segítségével sikerült megadnunk. E szimmetriafogalom kiépítéséhez magunk is hozzájárultunk. További szimmetriákat is találtunk, amelyek lehetővé teszik két vagy több mag (klaszter-szuperszimmetria), vagy különböző klaszterkonfigurációk (sokcsatornás dinamikai szimmetria) részletes spektrumának egységes leírását. Tanulmányoztuk kvantummechanikai rendszerek fázisátmeneteit, melyek a rendszereket jellemző szimmetria megváltozásának felelnek meg. Megvizsgáltuk a kvantummechanikai leírás kiterjesztésének némely (kvantumalgebrai) aspektusát is. Végül javasoltunk egy olyan osztályozási sémát, amely alkalmas a kvantummechanikai többtest-probléma sokféle szimmetriájának rendszerezésére. | We carried out investigations in order to contribute to our understanding on exotic nuclear decays, states and symmetries. We explored systematically the possible cluster configurations of some light and heavy nuclei. These investigations gave insight into the structural aspects of possible exotic decay modes. Besides the ground state of the selected nuclei, we also considered their superdeformed and hyperdeformed states. The connection between the cluster configurations and exotic states could be established by a rather general symmetry, called quasi-dynamical symmetry. We also contributed to the generalization of this concept. We developed further symmetries as well, that permit unified description of the detailed spectra of two or more nuclei (cluster-supersymmetry), or those of different cluster-configurations (multichannel dynamical symmetry). We studied the phase-transitions of some quantum mechanical systems, which correspond to the change of their characteristic symmetries. Furthermore, we investigated some (quantum-algebraic) aspects of the generalization of the quantum mechanical description. We proposed a framework that can serve for a systematic classification of many different kinds of symmetries of the quantum mechanical many-body problems
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