Back-angle anomaly and coupling between seven reaction channels of 12C + 24Mg using algebraic scattering theory

Lépine‐Szily, A.; Obuti, M.M.; Filho, R. Lichtenthaeler; Oliveira, J. M.; Villari, A.C.C.

doi:10.1016/0370-2693(90)90949-7

Cited by 22 publications

(3 citation statements)

References 15 publications

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“…[3−6] The angular distributions of the 12 C+ 24 Mg elastic, inelastic, and alpha-transfer reactions were reproduced fairly well within the coupled channel calculations using algebraic scattering theory. [7] The coupling between elastic and alpha-transfer channels [8,9] was used to explain the back-angle differential cross sections of different heavy-ion reactions.…”

Section: Introductionmentioning

confidence: 99%

Effect of Woods-Saxon Potential on the ¹⁶ O+ ²⁰ Ne Reaction Cross Section

Farra

2004

Commun. Theor. Phys.

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The excitation function and angular distributions for the 16O+20Ne system have been explained using the distorted wave Born approximation (DWBA) calculations. The real and imaginary Woods-Saxon optical potentials are assumed to be energy-dependent. The gross resonant structures observed in the 20Ne(16O,16O)20Ne excitation function are well described by the present DWBA calculations. Although the elastic and elastic-transfer analyses introduce a qualitative description of the experimental data, the coherent sum of the two reaction processes exhibit a much better result for both forward and large-angle data.

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Section: Introductionmentioning

confidence: 99%

Effect of Woods-Saxon Potential on the ¹⁶ O+ ²⁰ Ne Reaction Cross Section

Farra

2004

Commun. Theor. Phys.

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“…In this paper we present the results of an extensive phase-shift analysis of the 21 available angular distributions of the 12 C + 24 Mg elastic scattering [4,6,7,8] which show the clear transition that occurs between the two regimes. The phaseshift analysis was performed using a method we recently developed [9], which allows the determination of the elastic S-matrix elements and their associated errors, using a chi-square minimization algorithm specially developed for the scattering problem.…”

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confidence: 99%

“…This is an indication that a peripheral process is responsible for the oscillations observed at large angles. The coupling of alpha transfer channels to the elastic scattering can be the origin of this perturbation in the S-matrix [3,4,5,6]. On the other hand, the anomalous transparency at low energies shows a sensitivity of the elastic scattering to the nuclear interior, whose signatures in the S-matrix are a very rapid variation of the phases and strong oscillations in the reflection coefficients, in contrast to a typical strong absorption S-matrix, which is a smooth function of the angular momentum.…”

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confidence: 99%

Nuclear transparency and the onset of strong absorption regime in the12C+24Mgsystem

1999

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The elastic scattering of 12 C + 24 M g has been studied by means of a phaseshift analysis of 21 angular distributions ranging from E lab = 16 MeV up to E lab = 40 MeV. A tri-dimensional plot of the reflection coefficient of the Smatrix as a function of the angular momentum and the energy shows a well defined region of energy, which separates two regimes: strong absorption for higher energies and the so called "anomalous transparency regime", recently observed in this system at low energies. The Argand diagrams of the S-matrix in angular momentum space also present very contrasting behaviours in the two regions with very rapidly varying phases in the low energy region, which we associate with a parity dependent term in the S-matrix directly related to significant coupling to the elastic transfer of a 12 C nucleus. An anomalous transparency has been observed[1] in the12 C + 24 Mg system at energies around and slightly above the Coulomb barrier (E ≤ 1.5E b ). The angular distributions of the elastic scattering are characterized by oscillations and require a very small imaginary part in the optical potential in order to be fitted. These oscillations are present in practically the whole angular distribution, even at forward and intermediate angles, in contrast to the well-known phenomenon of Anomalous Large Angle Scattering (ALAS), which is observed at slightly higher energies (E ≥ 2.5E b ) and is characterized by oscillating angular distributions and excitation functions at large angles [2]. The oscillations observed in the angular distributions of the systems which exhibit ALAS phenomenon can be reproduced by a background strong absorption S-matrix plus a localized perturbation normally around the grazing angular 1

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