Fusion studies in C-12+W-182,W-184,W-186 reactions at energies below and near the Coulomb barrier

Background: The coupled-channels model has been highly successful in interpreting experimental subbarrier fusion. The statistical model framework has traditionally been used to explain the basic features of composite system de-excitation in the above Coulomb barrier region. However, in 12C-induced reactions with 182,186W, measured fusion cross sections are significantly lower than those predicted by various theoretical models and by fusion systematics. Purpose: To investigate the dynamics of heavy ion fusion at energies below and above the Coulomb barrier in the 12C-induced reactions. Method: A mass spectrometer was used to study the evaporation residues for the 12C ?+/- 182,184,186W reactions. The measurements ranged from 12% below to 45% above the Coulomb barrier energies. The measured fusion cross sections are compared with coupled channels and statistical model calculations. Results: The measured fusion cross sections for 12C +/- 182,184,186W reactions show reasonably good agreement with coupled-channel calculations. Also, evaporation residue cross sections for 12C & PLUSMN; 182,184,186W reactions in the present experiment along with the fission cross sections from literature are described by statistical model calculations. Conclusions: We successfully explain the previously reported discrepancy between fusion measurements and calculations based on various theoretical models and by fusion systematics for 12C & PLUSMN; 182,186W reactions.