Elastic scattering, inelastic excitation, and neutron transfer for Li 7 + Sn 120 at energies around the Coulomb barrier

Experimental angular distributions for the 7 Li + 120 Sn elastic and inelastic (projectile and target excitations) scattering, and for the neutron stripping reaction, have been obtained at E LAB = 20, 22, 24, and 26 MeV, covering an energy range around the Coulomb barrier ( V (LAB) B ≈ 21 . 4 MeV). Coupled channel and coupled reaction channel calculations were performed and both describe satisfactorily the experimental data sets. The 1 2 − state 7 Li inelastic excitation (using a rotational model), as well as the projectile coupling to the continuum ( α plus a tritium particle) play a fundamental role on the proper description of elastic, inelastic, and transfer channels. Couplings to the one-neutron stripping channel do not significantly affect the theoretical elastic scattering angular distributions. The spectroscopic amplitudes of the transfer channel were obtained through a shell model calculation. The theoretical angular distributions for the one-neutron stripping reaction agreed with the experimental data

Experimental study of He6+Be9 elastic scattering at low energies

New data for the He6+Be9 reaction at Elab=16.2 and 21.3 MeV have been taken and analyzed. The effect of the collective couplings to the excited states of the target has been studied by means of coupled-channels calculations, using a double-folding potential for the bare interaction between the colliding nuclei, supplemented with a phenomenological imaginary part of Woods-Saxon type. In addition, three- and four-body continuum-discretized coupled-channels calculations have been performed to investigate the effect of the projectile breakup on the elastic scattering. Both effects, the coupling to target and projectile excited states, are found to affect significantly the elastic scattering. The trivial local polarization potential extracted from the continuum-discretized coupled-channels calculations indicates that continuum couplings produce a repulsive real part and a long-range imaginary part in the projectile-target interaction. © 2011 American Physical Society.This work has been partially supported by the Spanish Ministerio de Ciencia e Innovacion´ under Projects FPA2009-07653 and PCI2006-A7-0654 and by the Spanish Consolider-Ingenio 2010 Programme CPAN (CSD2007-00042).Peer Reviewe

Spin-orbit effects in the 8Li+58Ni elastic scattering

In this work we present an elastic scattering angular distribution for the 8Li+58Ni system measured at Elab = 26.1 MeV. The 8Li beam was produced in the Radioactive Ion Beams in Brasil (RIBRAS) facility using the 7Li primary beam delivered by the 8-UD Pelletron accelerator. The angular distribution covers the angular range from 20 to 85 degrees in the center of mass frame. The data have been analysed by optical model and coupled channels calculations, including couplings to low-lying states in 8Li and the spin-orbit interaction. Our results indicate that the inclusion of the spin-orbit interaction in the calculations is important to describe the data at backward angles.Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) y Funda¸c˜ao de Amparo `a Pesquisa do Estado de S˜ao Paulo (FAPESP)013/22100-7 y 2016/17612-7Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior de Brasil (CAPES) y Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)-013/22100-7 y 2016/17612-

γ-Particle coincidence technique for the study of nuclear reactions

a b s t r a c t The Saci-Perere γ ray spectrometer (located at the Pelletron AcceleratorLaboratory -IFUSP) was employed to implement the γ-particle coincidence technique for the study of nuclear reaction mechanisms. For this, the Pd has been extracted and compared to coupled channel calculations using the São Paulo Potential (PSP), being reasonably well described by it

Reaction functions for weakly bound systems

We propose a new technique to analyze total reaction cross sections. In this technique, which has been previously applied to fusion reactions, the experimental data are used to build a dimensionless reaction function, which does not depend oil the system size or details of the optical potential. In this way, total reaction cross sections for different systems can be directly compared. We employ this technique to perform a systematic study of reaction cross sections of weakly bound systems in different mass ranges, and compare their reaction functions with the ones of tightly bound systems with similar masses. We show that breakup reactions and neutron transfers in halo systems lead to large reaction functions, well above the ones of typical tightly or weakly bound stable systems. (C) 2009 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPqFundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)FAPERJPRONEXConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Breakup effects in fusion and total reaction cross sections of weakly bound systems

We use a new technique to investigate the systematic behavior of near barrier complete fusion, total fusion and total reaction cross sections of weakly bound systems. A dimensionless fusion excitation function is used as a benchmark to which renormalized fusion data are compared and dynamic breakup effects can be disentangled from static effects. The same reduction procedure is used to study the effect of the direct reaction mechanisms on the total reaction cross section

Comparison of Nonmesonic Hypernuclear Decay Rates Computed in Laboratory and Center-of-Mass Coordinates

In this work we compute the one-nucleon-induced nonmesonic hypernuclear decay rates of He-5(Lambda), C-12(Lambda) and C-13(Lambda) using a formalism based on the independent particle shell model in terms of laboratory coordinates. To ascertain the correctness and precision of the method, these results are compared with those obtained using a formalism in terms of center-of-mass coordinates, which has been previously reported in the literature. The formalism in terms of laboratory coordinates will be useful in the shell-model approach to two-nucleon-induced transitions