RNS spin field ($h(S)=D/16$)

A worldsheet operator that changes fermion boundary conditions to the Ramond sector and creates a target spinor state. For $D$ real matter fermions its conformal weight is $D/16$. At $D=10$, combining it with the appropriate superghost factor gives a dimension-one spacetime-supersymmetry current.

In the critical RNS string, a spacetime supersymmetry generator is $Q_A=\oint e^{-{\varphi }_{\mathrm{gh}}/2}{S}_A$. The RNS spin field has weight $5/8$ and the superghost exponential has weight $3/8$, making a weight-one current. The GSO projection ensures the locality needed to act on retained vertex operators. Its operator products generate translations and relate NS sector and R sector states.