Virtual breakup to spin-singlet states in elastic scattering of deuterons from nuclei

Contributions to cross sections and analyzing powers from virtual breakup of deuterons to spin-singlet states are quantitatively investigated by the CDCC method in elastic scattering of deuterons at low and intermediate energies. Their effects are selectively remarkable in the tensor analyzing power Ayy. The invariant-amplitude method shows that the singlet-state breakup contribution behaves like TL-type tensor interactions in the scattering amplitude and the observables.