arXiv subjects

Taksu Cheon

Publications and source records attributed to Taksu Cheon.

99 records · Page 6Linked to original sources

arXiv1996

Wave Chaos in Quantum Billiards with Small but Finite-Size Scatterer

We study the low energy quantum spectra of two-dimensional rectangular billiards with a small but finite-size scatterer inside. We start by examining the spectral properties of billiards with a single pointlike scatterer. The problem is formulated in terms of self-adjoint extension theory of functional analysis. The condition for the appearance of so-called wave chaos is clarified. We then relate the pointlike scatterer to a finite-size scatterer through the appropriate truncation of basis. We show that the signature of wave chaos in low energy states is most prominent when the scatterer is weakly attractive. As an illustration, numerical results of a rectangular billiard with a small rectangular scatterer inside are exhibited.

chao-dyn↗

arXiv1995

Response Function of Asymmetric Nuclear Matter

The charge longitudinal response function is examined in the framework of the random-phase approximation in an isospin-asymmetric nuclear matter where proton and neutron densities are different. This asymmetry changes the response through both the particle-hole interaction and the free particle-hole polarization propagator. We discuss these two effects on the response function on the basis of our numerical results in detail.

nucl-th↗

arXiv1995

Nuclear Mass Dependence of Chaotic Dynamics in Ginocchio Model

The chaotic dynamics in nuclear collective motion is studied in the framework of a schematic shell model which has only monopole and quadrupole degrees of freedom. The model is shown to reproduce the experimentally observed global trend toward less chaotic motion in heavier nuclei. The relation between current approach and the earlier studies with bosonic models is discussed.

nucl-th↗

arXiv1995

Level spacing distribution of pseudointegrable billiard

In this paper, we examine the level spacing distribution $P(S)$ of the rectangular billiard with a single point-like scatterer, which is known as pseudointegrable. It is shown that the observed $P(S)$ is a new type, which is quite different from the previous conclusion. Even in the strong coupling limit, the Poisson-like behavior rather than Wigner-like is seen for $S>1$, although the level repulsion still remains in the small $S$ region. The difference from the previous works is analyzed in detail.

chao-dyn↗

arXiv1995

Classical and Quantal Irregular Scatterings with Complex Target

One-dimensional scattering by a target with two internal degrees of freedom is investigated. The damping of resonance peaks and the associated appearance of the fluctuating background in the quantum inelastic scattering amplitudes are found. Examination of the analog classical system reveals a disorderly reaction function, which is then related to the quantum amplitude through a semiclassical argument.

nucl-th↗

arXiv1995

Isospin dependent effective interaction in nucleon-nucleus scattering

The isospin-dependent component of the effective nucleon-nucleon interaction that causes the $ΔT=1$ (p, p') and (p, n) reactions off nuclei is studied. It is shown that the corrections to the impulse approximation comes from the $g$-matrix type correction and the rearrangement term. They are numerically estimated with the isospin-asymmetric nuclear-matter reaction matrix approach. The analysis of the isobaric analog transitions ${}^{42}$Ca(p,n)${}^{42}$Sc and ${}^{48}$Ca(p,n)${}^{48}$Sc are presented.

nucl-th↗

arXiv1995

Folded Bifurcation in Coupled Asymmetric Logistic Maps

A system of coupled two logistic maps, one periodic and the other chaotic, is studied. It is found that with the variation of the coupling strength, the system displays several curious features such as the appearance of quadrupling of period, occurrence of isolated period three attractor and the coexistence of the Hopf and pitchfork bifurcations. Possible applications and extensions are discussed.

chao-dyn↗

arXiv1995

Scale Anomaly and Quantum Chaos in the Billiards with Pointlike Scatterers

We argue that the random-matrix like energy spectra found in pseudointegrable billiards with pointlike scatterers are related to the quantum violation of scale invariance of classical analogue system. It is shown that the behavior of the running coupling constant explains the key characteristics of the level statistics of pseudointegrable billiards.

hep-th↗

arXiv1995

Geometric Phase in Quantum Billiards with a Pointlike Scatterer

We examine the quantum energy levels of rectangular billiards with a pointlike scatterer in one and two dimensions. By varying the location and the strength of the scatterer, we systematically find diabolical degeneracies among various levels. The associated Berry phase is illustrated, and the existence of localized wave functions is pointed out. In one dimension, even the ground state is shown to display the sign reversal with a mechanism to circumvent the Sturm-Liouville theorem.

hep-th↗