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The electromagnetic excitation of the two-phonon isovector giant dipole resonance in relativistic projectiles incident on heavy targets can be proceed via several intermediate $1^-$ one-phonon giant resonance states. In two step electric…

Nuclear Theory · Physics 2009-10-30 C. A. Bertulani , V. Yu. Ponomarev , V. V. Voronov

A Bayesian analysis of the world's p(gamma,K+)Lambda data is presented. We adopt a Regge-plus-resonance framework featuring consistent couplings for nucleon resonances up to spin J=5/2, and evaluate 2048 model variants considering all…

Nuclear Theory · Physics 2012-12-18 Pieter Vancraeyveld , Lesley De Cruz , Jan Ryckebusch , Tom Vrancx

The s-wave meson-nucleon interaction in the S=-1 sector is studied by means of a coupled-channel Lippmann Schwinger equation, using the lowest order chiral Lagrangian and a cut off to regularize the loop integrals. The position and width of…

Nuclear Theory · Physics 2007-05-23 A. Ramos , E. Oset

Some recent advancements of the nuclear many-body theory and selected results on nuclear giant and pygmy resonances are presented. The theory is compactly reviewed, with a special focus on the emergent scale of the quasiparticle-vibration…

Nuclear Theory · Physics 2025-12-30 Elena Litvinova

I present a brief summary of the first three decades of studies of pygmy resonances in nuclei and their relation to the symmetry energy of nuclear matter. I discuss the first experiments and theories dedicated to study the electromagnetic…

Nuclear Theory · Physics 2020-01-08 C. A. Bertulani

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase…

Nuclear Theory · Physics 2018-12-05 N. N. Arsenyev , A. P. Severyukhin , V. V. Voronov , Nguyen Van Giai

Isoscalar and isovector monopole oscillations that correspond to giant resonances in spherical nuclei are described in the framework of time-dependent relativistic mean-field (RMF) theory. Excitation energies and the structure of eigenmodes…

Nuclear Theory · Physics 2009-10-30 D. Vretenar , G. A. Lalazissis , R. Behnsch , W. Pöschl , P. Ring

Photoneutron reactions on $^{208}$Pb in the Giant Dipole Resonance energy region have been investigated at the $\gamma$-ray beam line of the NewSUBARU facility in Japan. The measurements made use of quasi-monochromatic laser Compton…

Reaction-rate calculations relevant to r-process nucleosynthesis depend sensitively on the nuclear $\gamma$-strength function ($\gamma$SF). Here we investigate the impact of low-lying pygmy dipole strength (PDS) in $(n,\gamma)$ and…

Nuclear Theory · Physics 2026-03-16 T. Ghosh , A. Kaur , N. Paar

We study the correlation between the neutron skin development and the low-energy dipole response associated with the pygmy dipole resonance (PDR) in connection with the properties of symmetry energy. We perform our investigation within a…

Nuclear Theory · Physics 2015-06-16 V. Baran , M. Colonna , M. Di Toro , A. Croitoru , D. Dumitru

We consider atoms or molecules coupled to the quantized electromagnetic radiation field in a dipole approximation. We show the existence of ground states and resonance states in situations where the eigenvalues are degenerate and protected…

Mathematical Physics · Physics 2025-07-08 David Hasler , Markus Lange

The collective excitation phenomena in atomic nuclei are studied in two different formulations of the Random Phase Approximation (RPA): (i) RPA based on correlated realistic nucleon-nucleon interactions constructed within the Unitary…

Nuclear Theory · Physics 2009-11-11 N. Paar , P. Papakonstantinou , H. Hergert , R. Roth

A new version of random phase approximation is proposed for low-energy harmonic vibrations in nuclei. The theory is not based on the quasi-particle vacuum of the BCS/HFB ground state, but on the pair condensate determined in Ref. [4]. The…

Nuclear Theory · Physics 2013-06-27 L. Y. Jia

We review a recent progress in investigation of the isoscalar toroidal dipole resonance (TDR). A possible relation of the TDR and low-energy dipole strength (also called a pygmy resonance) is analyzed. It is shown that the dipole strength…

Nuclear Theory · Physics 2017-06-05 V. O. Nesterenko , J. Kvasil , A. Repko , W. Kleinig , P. -G. Reinhard

The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o(4)*su(2)_I. The spins of the resonances are obtained…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. Kirchbach

Low-energy dipole excitations have been investigated theoretically in N=50, several N=82 isotones and the Z=50 Sn isotopes. For this purpose a method incorporating both HFB and multi-phonon QPM theory is applied. A concentration of…

Nuclear Theory · Physics 2008-11-26 N. Tsoneva , H. Lenske

The proton-neutron relativistic quasiparticle random phase approximation (PN-RQRPA) is formulated in the canonical single-nucleon basis of the relativistic Hartree-Bogoliubov (RHB) model, for an effective Lagrangian characterized by…

Nuclear Theory · Physics 2009-02-18 N. Paar , T. Niksic , D. Vretenar , P. Ring

In order to study isovector dipole response of neutron-rich nuclei, we have applied a time-dependent method of antisymmetrized molecular dynamics. The dipole resonances in Be, B and C isotopes have been investigated. In $^{10}$Be, $^{15}$B,…

Nuclear Theory · Physics 2009-11-11 Y. Kanada-En'yo , M. Kimura

The isoscalar dibaryon resonance $D_{03}(2380)$, discovered at WASA@COSY in the total cross section of the reaction $pn\to d\pi^0\pi^0$ and in the elastic pn scattering in the energy range corresponding to the invariant mass of the pn…

Nuclear Theory · Physics 2025-11-04 Yu. N. Uzikov , A. A. Temerbayev , N. T. Tursunbayev

We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations,$\gamma$-vibrational $K^{\pi}=2^+$ states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed…

Nuclear Theory · Physics 2017-11-21 A. Repko , J. Kvasil , V. O. Nesterenko , P. -G. Reinhard