Gamow shell model description of $^4$He($d$,$d$) elastic scattering reactions

Structure of weakly bound/unbound light nuclei is often related to the low-energy decay channels involving composite particles like deuteron or ${\alpha}$-particle. These channels are essential to understand the appearance of light nuclei in the Big Bang nucleosynthesis or the helium fusion. We generalize the Gamow shell model (GSM) in coupled-channel (GSM-CC) representation to include reaction channels with the composite particles. In the core + valence particle formulation, this unified microscopic approach for structure and reactions involving weakly bound/unbound nuclei can be also applied to study low-energy properties of heavy nuclei. As the first application of this generalized GSM-CC approach, we describe the structure of 6Li and deuteron - ${\alpha}$-particle elastic scattering using the same effective Furutani-Horiuchi-Tamagaki (FHT) type nucleon-nucleon interaction. Asymptotically, the deuteron structure including its continuum is described using the N3LO chiral force. The bulk of the data, including low-energy spectrum of 6Li, asymptotic normalization coefficients, and angular differential cross sections are satisfactorily described.