Radiative capture reaction for 17^{17}Ne formation within a full three-body model

Background: The breakout from the hot Carbon-Nitrogen-Oxigen (CNO) cycles can trigger the rp-process in type I x-ray bursts. In this environment, a competition between $^{15}\text{O}(\alpha,\gamma){^{19}\text{Ne}}$ and the two-proton capture reaction $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$ is expected. Purpose: Determine the three-body radiative capture reaction rate for ${^{17}\text{Ne}}$ formation including sequential and direct, resonant and non-resonant contributions on an equal footing. Method: Two different discretization methods have been applied to generate $^{17}$Ne states in a full three-body model: the analytical transformed harmonic oscillator method and the hyperspherical adiabatic expansion method. The binary $p$--$^{15}$O interaction has been adjusted to reproduce the known spectrum of the unbound $^{16}$F nucleus. The dominant $E1$ contributions to the $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$ reaction rate have been calculated from the inverse photodissociation process. Results: Three-body calculations provide a reliable description of $^{17}$Ne states. The agreement with the available experimental data on $^{17}$Ne is discussed. It is shown that the $^{15}\text{O}(2p,\gamma){^{17}\text{Ne}}$ reaction rates computed within the two methods agree in a broad range of temperatures. The present calculations are compared with a previous theoretical estimation of the reaction rate. Conclusions: It is found that the full three-body model provides a reaction rate several orders of magnitude larger than the only previous estimation. The implications for the rp-process in type I x-ray bursts should be investigated.Comment: 10 pages, 10 figures. Corrected versio

The continuum description with pseudo-state wave functions

Benchmark calculations are performed aiming to test the use of two different pseudo-state bases on the the Multiple Scattering expansion of the total Transition amplitude (MST) scattering framework. Calculated differential cross sections for p-6He inelastic scattering at 717 MeV/u show a good agreement between the observables calculated in the two bases. This result gives extra confidence on the pseudo-state representation of continuum states to describe inelastic/breakup scattering.Comment: 4 pages, 2 figures. Published in Physical Review

Multiple scattering effects in quasi free scattering from halo nuclei: a test to Distorted Wave Impulse Approximation

Full Faddeev-type calculations are performed for $^{11}$Be breakup on proton target at 38.4, 100, and 200 MeV/u incident energies. The convergence of the multiple scattering expansion is investigated. The results are compared with those of other frameworks like Distorted Wave Impulse Approximation that are based on an incomplete and truncated multiple scattering expansion.Comment: 7 pages, 16 figures, to be published in Phys. Rev.

Four-body continuum-discretized coupled-channels calculations using a transformed harmonic oscillator basis

The scattering of a weakly bound three-body system by a target is discussed. A transformed harmonic oscillator basis is used to provide an appropriate discrete and finite basis for treating the continuum part of the spectrum of the projectile. The continuum-discretized coupled channels framework is used for the scattering calculations. The formalism is applied to different reactions, 6He+12C at 229.8 MeV, 6He+64Zn at 10 and 13.6 MeV, and 6He+208Pb at 22 MeV, induced by the Borromean nucleus 6He. Both the Coulomb and nuclear interactions with a target are taken into account.Comment: Published in Phys. Rev.

Study of reactions induced by 6He on 9Be

INPC 2013 – International Nuclear Physics ConferenceWe present the results of experiments using a 6He beam on a 9Be target at energies 7 − 9 times the Coulomb barrier. Angular distributions of the elastic, inelastic scattering (target breakup) and the a-particle production in the 6He+9Be collision have been analysed. Total reaction cross sections were obtained from the elastic scatteringanalyses and a considerable enhancement has been observed by comparing to stable system

Elastic scattering, inelastic excitation, and 1 n pick-up transfer cross sections for 10 B + 120 Sn at energies near the Coulomb barrier

The 10 B + 120 Sn reaction has been systematically studied at laboratory energies around the Coulomb barrier: E LAB = 31.5 , 33.5, 35.0, and 37.5 MeV. Cross sections for the elastic scattering and some reaction processes have been measured: excitation to the 1 + state of 10 B ; excitation to the 2 + and 3 − states of 120 Sn ; and the one-neutron pick-up transfer 120 Sn ( 10 B , 11 B ) 119 Sn . Coupled reaction channel (CRC) calculations have been performed in the context of the double-folding São Paulo potential. The theoretical calculations result in a good overall description of the experimental angular distributions. The effect on the theoretical elastic-scattering angular distributions of couplings to the inelastic and transfer states (through the CRC calculations) and to the continuum states (through continuum-discretized coupled-channels calculations) has been investigated.Instituto Nacional de Ciência e Tecnologia–Física Nuclear e Aplicações (INCT-FNA) 464898/2014-5Ministerio de Economía y Competitividad de España y el Fondo Europeo de Desarrollo Regional (FEDER) FIS2014-51941-P,Junta de Andalucía. FQM-160Programa de investigación e innovación de la Unión Europea Horizonte 2020. 65400

Exotic Nuclei in South America

The Radioactive Ion Beams in Brasil (RIBRAS) is described. Experiments using radioactive secondary beams of light rare isotopes such as 6He, 7Be, 8Li on several targets have been performed and the results are presented

Probing 6He structure from proton inelastic collisions

We explore the Hyperspherical Harmonics pseudostate method to describe the 6He continuum. The method is use it within the multiple scattering of the transition amplitude (MST) approach to study inelastic scattering of p-6He at 700 MeV/u.Fundaçao para a Ciência e Tecnologia (FCT) POCTI/FNU/43421/200