Resumo

GOMEZ CAMACHO, A.; AGUILERA, E.F.  e  QUIROZ, E.M.. DWBA-calculations of elastic scattering, fusion and breakup cross sections for reactions involving weakly bound stable projectiles around the barrier energy. Rev. mex. fis. [online]. 2006, vol.52, suppl.4, pp.30-37. ISSN 0035-001X.

A simultaneous Distorted Wave Born Approximation calculation of elastic scattering, fusion and breakup cross sections for energies above and below the Coulomb barrier energy is presented for reactions involving weakly bound projectiles on heavy targets. In the approach, a Woods-Saxon optical potential U is used where its imaginary part W is split into a volume part W_F which is only responsible for fusion absorption and a surface part Wdr which accounts for direct reactions. The fusion and direct reaction cross sections are calculated in terms of W_F and W_DR respectively. The optical potential parameters are determined from a simultaneous -analysis of recent experimental data of elastic scattering and fusion cross sections. From this, energy dependent forms for W_F (E) and W_DR (E) can be determined and by the dispersion relation the corresponding real polarization potentials V_F (E) and V_DR (E) are also found. The appearance or absence of the threshold anomaly can therefore be extracted from these energy dependent forms. By turning on and off the potentials responsible for breakup reactions (V_DR and W_DR) the effect of breakup on fusion can be studied. So, regions of suppresion and of enhancement around the barrier energy can be determined for the nuclear systems under study.

Palavras-chave : Nuclear reactions; exotic nuclei; threshold anomaly.

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