We present a novel method of smoothing discrete breakup cross sections calculated by the method of continuum-discretized coupled channels. The smoothing method based on the complex scaling method is tested with success for a ${}^{58}\mathrm{Ni}$($d,\mathit{pn}$) reaction at $80$ MeV as an example of three-body breakup reactions and applied to a ${}^{12}\text{C}({}^6\text{He},\mathit{nn}\hspace{0.5em}{}^4\text{He})$ reaction at $229.8$ MeV as an example of four-body breakup reactions. Fast convergence of the breakup cross section with respect to extending the model space is confirmed. The method is also applied to ${}^{12}\text{C}({}^6\text{He},\mathit{nn}\hspace{0.5em}{}^4\text{He})$ and ${}^{208}\text{Pb}({}^6\text{He},\mathit{nn}\hspace{0.5em}{}^4\text{He})$ reactions at $240$ MeV/$A$ and compared with the experimental data.

• Received 2 June 2010

DOI:https://doi.org/10.1103/PhysRevC.82.051602