On light-cone SFT contact terms in a plane wave

Testing the BMN correspondence at non-zero string coupling g_s requires a one-loop string field theory calculation. At order g_s ², matrix elements of the light-cone string field theory hamiltonian between single-string states receive two contributions: the iterated cubic interaction, and a contact term {Q, Q̄} whose presence is dictated by supersymmetry. In this paper we calculate the leading large μp ⁺α′ contribution from both terms for the set of intermediate states with two string excitations. We find precise agreement with the basis-independent order g₂² results from gauge theory.