Full Self-Consistent Study of Isobaric Analog Resonances

Physics of Atomic Nuclei - Fully self-consistent framework for isobaric-analog resonances is presented. The chains of parent neutron-rich Ca, Ni, Sn nuclei around the neutron shells at $$N=20$$ ,...     

Self-Consistent Description of Isobaric Analog Resonances in Neutron-Rich Nuclei with Pairing

Physics of Atomic Nuclei - A self-consistent approach to describing isobaric analog resonances (IAR) in neutron-rich nuclei that involve pairing is developed. The continuum quasiparticle...     

On Tensor Correlations in the Formation of Charge-Exchange Giant Spin-Multipole Resonances in Medium-Heavy Magic Parent Nuclei

Physics of Atomic Nuclei - An approach to taking into account tensor correlations in the formation of charge-exchange giant spin-multipole resonances in medium-heavy magic parent nuclei is proposed...     

Resonance Structure of the Charge-Exchange Strength Function

Physics of Atomic Nuclei - The resonance structure of the charge-exchange strength function S(E) is studied. Three types of isobaric resonances are considered within the self-consistent theory of...     

Effect of the Tensor Force on Charge-Exchange Spin-Dependent Multipole Excitations

The charge-exchange spin-dipole （SD） and spin-quadrupole （SQ） strength functions of 90Zr are calculated with and without the tensor terms of the Skyrme interaction in self-consistent HF＋RPA approach. It is found that, in SD and SQ transitions, the RPA correlations associated with the tensor terms shin dramatically the strengths of （Ylσ）λ = l？1 and （Ylσ）λ = 1 modes upward and downward, respectively, and also shift the strengths of （Ylσ）λ = l ＋ 1 modes upward. The coupling between （Yl = λ ？ 1σ）λ and （Yl = λ ＋ 1σ）λ modes arising from the tensor correlation is noticeable. The RPA tensor correlations produce strengths of SD and SQ modes, which are distributed in a much wider energy range, and the （Ylσ）λ = l ？ 1 modes dominate the high energy part of the strength functions. These energy shifts and coupling effects of different modes can be understood qualitatively by expressing a finite range tensor force in a separable form.     

Resonances within chaos

A chaotic system under periodic forcing can develop a periodically visited strange attractor. We discuss simple models in which the phenomenon, quite easy to see in numerical simulations, can be completely studied analytically.     

Degenerate Elliptic Resonances

Quasi-periodic motions on invariant tori of an integrable system of dimension smaller than half the phase space dimension may continue to exist after small perturbations. The parametric equations of the invariant tori can often be computed as a formal power series in the perturbation parameter and can be given a meaning via resummations. Here we prove that, for a class of elliptic tori, a resummation algorithm can be devised and proved to be convergent, thus extending to such lower-dimensional invariant tori the methods employed to prove convergence of the Lindstedt series either for the maximal (i.e. KAM) tori or for the hyperbolic lower-dimensional invariant tori.     

Resonances: Calculations and Observables

Methods to calculate resonances energies, decay widths, and corresponding wave functions, are discussed in realistic problems. Proton radioactivity from deformed drip-line nuclei described as decay of a resonant state of the proton in the field of the daughter nucleus, is used to test the models and to show that all experimental data currently available can be consistently described.     

Semimicroscopic Description of High-Energy Charge-Exchange Spin-Monopole Excitations in Medium-Heavy Spherical Nuclei

Physics of Atomic Nuclei - The semimicroscopic particle–hole dispersive optical model developed recently is applied to describing main properties of the Gamow–Teller and charge-exchange...     

The Flux-Across-Surfaces Theorem and Zero-Energy Resonances

In this contribution we shall first introduce the Flux Across Surfaces (FAS) theorem, placing it in the general context of the Quantum Scattering Theory. Then we shall review briefly the theory of resonances in non-relativistic Quantum Mechanics and outline a proof of the FAS theorem for non-relativistic potential scattering, which covers also the case in which there is a zero energy resonance.     

Clusters as Many-Body Resonances

A formalism to evaluate the resonant states produced by two particles moving outside a closed shell core is presented. The two-particle states are calculated by using a single-particle representation consisting of bound states, Gamow resonances and scattering states in the complex energy plane (Berggren representation). Two representative cases are analysed corresponding to whether the Fermi level is below or above the continuum threshold. It is found that long-lived resonances are mostly determined by either bound states or by narrow Gamow resonances. However, they are significantly affected by wide resonances and the continuum background itself.     

Resonances in Positron-Mg Scattering

We present the results for resonances in positron-Mg scattering at low impact energy （0-5.0eV） by using the momentum space coupled-channel optical （CCO） method in momentum space. The S-partial wave resonance at 3.880eV, P-partial wave resonance at 4.020eV, and D-partial wave resonance at 4.267eV are found.     

Resonances in Positron-He Scattering

We present the results for resonances in positron-He scattering at low impact energy （19.3-24.0eV） by using the momentum space coupled-channel optical （CCO） method. The S-partial wave resonance at 20.16 eV is found for the first time.     

Resonances in chaotic dynamics

We present a discussion and some numerical results on the actual possibility of making accessible, by numerical techniques, the complex singularities of the power spectrum (resonances) for a chaotic signal. Hénon's transformation is investigated in detail, showing that the position of the leading resonance in the complex frequency plane determines the kind of mixing rate in the time evolution.