LAUSR

A bstractWe provide the covariant superspace equations that are sufficient to determine the complete θ expansion of the vertex operator of the open string massive states with (mass)2 = 1/α′ in pure spinor formalism of superstring theory. These equations get rid of the redundant degrees of freedom in superfields and are consistent with the BRST conditions derived in [1]. Further, we give the explicit θ expansion of the superfields appearing in the unintegrated vertex to O(θ3). Finally, we compute the contribution to a 3-point tree amplitude with the resulting vertex operator upto O(θ3) and find its kinematic structure to be identical to the corresponding RNS computation.