An R-symmetry acts nontrivially on the supersymmetry generators. In four-dimensional N=1 supersymmetry, the superspace coordinate has R-charge one, so a superpotential must have R-charge two.
R-charge is the charge under a continuous R-symmetry. In four-dimensional N=1 supersymmetry, the fermion in a chiral multiplet has R-charge one less than its scalar, and every superpotential term has R-charge two.
A scalar chiral primary operator at a four-dimensional N=1 superconformal fixed point saturates a shortening bound and obeys .
