Couplings in D(2, 1; α) superconformal mechanics from the SU(2) perspective

Dynamical realizations of the most general N = 4 superconformal group in one dimension D(2, 1; α) are reconsidered from the perspective of the R-symmetry subgroup SU(2). It is shown that any realization of the R-symmetry subalgebra in some phase space can be extended to a representation of the Lie superalgebra corresponding to D(2, 1; α). Novel couplings of arbitrary number of supermultiplets of the type (1, 4, 3) and (0, 4, 4) to a single supermultiplet of either the type (3, 4, 1), or (4, 4, 0) are constructed. D(2, 1; α) superconformal mechanics describing superparticles propagating near the horizon of the extreme Reissner-Nordström-AdS-dS black hole in four and five dimensions is considered. The parameter α is linked to the cosmological constant.