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The pygmy dipole resonance in neutron-rich nuclei is studied within the framework of the Vlasov equation which is solved numerically. The interaction used in the Thomas-Fermi ground state and in the Vlasov equation is derived from an energy…

Nuclear Theory · Physics 2012-03-26 Michael Urban

We discuss, in an investigation based on Vlasov equation, the properties of the isovector modes in nuclear matter and atomic nuclei in relation with the symmetry energy. We obtain numerically the dipole response and determine the strength…

Nuclear Theory · Physics 2015-06-22 V. Baran , M. Colonna , M. Di Toro , B. Frecus , A. Croitoru , D. Dumitru

The pygmy dipole resonances and photon strength functions in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite fermi systems which includes phonon coupling…

The $\gamma$-ray strength function ($\gamma$SF) is essential for understanding the electromagnetic response in atomic nuclei and modeling astrophysical neutron capture rates. We introduced a microscopic description of both electric dipole…

Nuclear Theory · Physics 2025-04-02 Amandeep Kaur , Esra Yüksel , Nils Paar

Low-energy dipole excitations are analyzed for the stable isotopes $^{40}$Ca and $^{48}$Ca in the framework of the Skyrme-second random-phase approximation. The corresponding random-phase approximation calculations provide a negligible…

Nuclear Theory · Physics 2015-05-28 D. Gambacurta , M. Grasso , F. Catara

The accurate characterization of the nuclear symmetry energy and its density dependence is one of the outstanding open problems in nuclear physics. A promising nuclear observable in order to constrain the density dependence of the symmetry…

Nuclear Theory · Physics 2012-02-15 X. Roca-Maza , M. Brenna , M. Centelles , G. Colo' , K. Mizuyama , G. Pozzi , X. Viñas , M. Warda

Electric dipole strength near the neutron separation energy significantly impacts nuclear structure properties and astrophysical scenarios. These excitations are complex in nature and may involve the so-called pygmy dipole resonance (PDR).…

Nuclear Theory · Physics 2025-02-12 Eun Jin In , Emanuel Chimanski , Jutta Escher , Sophie Péru , Aaina Thapa , Walid Younes

The multipole response of nuclei at temperatures T=0-2 MeV is studied using a self-consistent finite-temperature RPA (random phase approximation) based on relativistic energy density functionals. Illustrative calculations are performed for…

Nuclear Theory · Physics 2010-02-26 Y. F. Niu , N. Paar , D. Vretenar , J. Meng

Large-scale calculations of the E1 strength are performed within the random phase approximation (RPA) based on the relativistic point-coupling mean field approach in order to derive the radiative neutron capture cross sections for all…

Nuclear Theory · Physics 2015-06-11 I. Daoutidis , S. Goriely

We have computed dipole strength distributions for nickel and tin isotopes within the Relativistic Quasiparticle Time Blocking approximation (RQTBA). These calculations provide a good description of data, including the neutron-rich tin…

The gamma strength function and level density of 1- states in 96Mo have been extracted from a high-resolution study of the (p,p') reaction at 295 MeV and extreme forward angles. By comparison with compound nucleus $\gamma$ decay…

Level density and radiative strength functions which allow precise reproduction of the two-step cascade intensity, gamma width of compound state and cascade population of levels up to excitation energy of about 3.5 MeV were determined using…

Nuclear Experiment · Physics 2007-05-23 V. A. Khitrov , A. M. Sukhovoj , Pham Dinh Khang , Vuong Huu Tan , Nguyen Xuan Hai

The isotopic dependence of the isovector Pygmy dipole response in tin is studied within the framework of the relativistic random phase approximation. Regarded as an oscillation of the neutron skin against the isospin-symmetric core, the…

Nuclear Theory · Physics 2009-11-11 J. Piekarewicz

The $\gamma$-ray strength function ($\gamma$SF) and nuclear level density (NLD) have been extracted for the first time from inverse kinematic reactions with the Oslo Method. This novel technique allows measurements of these properties…

The isotopic dependence of the excitation energies of the pygmy dipole resonance (PDR) is analyzed in the framework of the self-consistent relativistic Hartree-Bogoliubov (RHB) model and the relativistic quasiparticle random-phase…

Nuclear Theory · Physics 2011-07-19 N. Paar , T. Niksic , D. Vretenar , P. Ring

The electric dipole excitation of various nuclei is calculated with a Random Phase Approximation phenomenological approach. The evolution of the strength distribution in various groups of isotopes, oxygen, calcium, zirconium and tin, is…

Nuclear Theory · Physics 2009-08-18 G. Co' , V. De Donno , C. Maieron , M. Anguiano , A. M. Lallena

A survey of some results in the modern microscopic theory of properties of nuclear reactions with gamma-rays is given. First of all, we discuss the impact of phonon coupling (PC) on the photon strength function (PSF) because it represents…

Nuclear Theory · Physics 2016-09-21 Sergei Kamerdzhiev , Oleg Achakovskiy , Alexander Avdeenkov , Stephane Goriely

The prediction of cross sections for nuclei far off stability is crucial in the field of nuclear astrophysics. In recent calculations the nuclear level density -- as an important ingredient to the statistical model (Hauser-Feshbach) -- has…

Astrophysics · Physics 2016-08-30 T. Rauscher , F. -K. Thielemann , K. -L. Kratz

Dipole excitations below the neutron threshold in neutron rich Sn isotopes are studied theoretically in the Quasiparticle-Phonon Model with HFB single particle input. Of special interest are the low-lying two-phonon 1- states and the Pygmy…

Nuclear Theory · Physics 2014-11-18 N. Tsoneva , H. Lenske , Ch. Stoyanov

Recently, new low-energy modes of excitation called pygmy resonances have been observed. Their distinct feature is the close connection to nuclear skin oscillations. A successful description of the pygmy resonances could be achieved in a…

Nuclear Theory · Physics 2014-10-15 Nadia Tsoneva , Horst Lenske