相关论文: Anharmonicities of giant dipole excitations
We study the effect of the spreading widths on the excitation probabilities of the double giant dipole resonance. We solve the coupled-channels equations for the excitation of the giant dipole resonance and the double giant dipole…
Using a microscopic approach beyond RPA to treat anharmonicities, we mix two-phonon states among themselves and with one-phonon states. We also introduce non-linear terms in the external field. These non-linear terms and the anharmonicities…
Double-$\gamma$ vibrations in deformed nuclei are analyzed in the context of the interacting boson model. A simple extension of the original version of the model towards higher-order interactions is required to explain the observed…
We perform microscopic calculations of the inelastic cross sections for the double and triple excitation of giant resonances induced by heavy ion probes within a semicalssical coupled channels formalism. The channels are defined as…
A simple method for the calculation of higher orders of the logarithmic perturbation theory for bound states of the spherical anharmonic oscillator is developed. The structure of the perturbation series for energy eigenvalues of the sextic…
The effect of deformation on the excitation of multiple giant dipole resonances is studied. Analytical expressions are derived in the framework of the interacting boson model for the energies and E1 properties of giant dipole resonances in…
We theoretically and experimentally examine the effects of anharmonic terms in the trapping potential for linear chains of trapped ions. We concentrate on two different effects that become significant at different levels of anharmonicity.…
We report on the first microscopic study of the properties of two-phonon giant resonances in deformed nuclei. The cross sections of the excitation of the giant dipole and the double giant dipole resonances in relativistic heavy ion…
Double-$\gamma$ vibrations in deformed nuclei are studied in the context of the interacting boson model with special reference to their anharmonic character. It is shown that large anharmonicities can be obtained with interactions that are…
In this letter, we show that the non-linearitites of large amplitude motions in atomic nuclei induce giant quadrupole and monopole vibrations. As a consequence, the main source of anharmonicity is the coupling with configurations including…
Multi-electron giant dipole resonances of atoms in crossed electric and magnetic fields are investigated. Stationary configurations corresponding to a highly symmetric arrangement of the electrons on a decentered circle are derived, and a…
Double-dipole excitations in ^{208}Pb are analyzed within a microscopic model explicitly treating 2p2h-excitations. Collective states built from such 2p2h-excitations are shown to appear at about twice the energy of the isovector giant…
A previously developed approach for the numerical treatment of two particles that are confined in a finite optical-lattice potential and interact via an arbitrary isotropic interaction potential has been extended to incorporate an…
A systematic microscopic study of the anharmonic properties of the double giant dipole resonance (DGDR) has been carried out, for the first time, for nuclei with mass number $A$ spanning the whole mass table. It is concluded that the…
The role of anharmonicity on superconductivity has often been disregarded in the past. Recently, it has been recognized that anharmonic decoherence could play a fundamental role in determining the superconducting properties (electron-phonon…
The problem of the effect of two-frequency quasi-periodic perturbations on systems close to arbitrary nonlinear two-dimensional Hamiltonian ones is studied in the case when the corresponding perturbed autonomous systems have a double limit…
A new class of giant resonances in nuclei, namely double giant resonances, is discussed. They are giant resonances built on top of other giant resonances. Investigation on their properties, together with similar studies on low-lying…
The interplay of nuclear and Coulomb processes in the inelastic excitation of single- and double-phonon giant resonances in heavy ion collisions is studied within a simple reaction model. Predominance of the Coulomb excitation mechanism on…
A new class of giant resonances in nuclei is discussed, i.e., giant resonances built on other giant resonances. These resonances are observed with very large cross sections in relativistic heavy ion collisions. A great experimental and…
Multi-electron giant dipole resonances of atoms in crossed electric and magnetic fields are investigated. Stationary configurations corresponding to a highly symmetric arrangement of the electrons on a decentered circle are derived, and a…