The $S$ matrices of elastic $\alpha$-${}^{12}$C scattering at low energies in effective field theory

The elastic $\alpha$-${}^{12}$C scattering at low energies for $l=0,1,2,3,4,5,6$ is studied in effective field theory. We discuss the construction of the $S$ matrices of elastic $\alpha$-${}^{12}$C scattering in terms of the amplitudes of sub-threshold bound and resonant states of ${}^{16}$O, which are calculated from the effective Lagrangian. The parameters appearing in the $S$ matrices are fitted to the phase shift data below the $p$-${}^{15}$N breakup threshold energy, and we find that the phase shifts are well described within the theory.