We reconsider the two-point string scattering amplitudes of massless Neveu-Schwarz–Neveu-Schwarz states of Type IIB orientifold superstring theory on the disk and projective plane in ten dimensions and analyse its ${\alpha }^{\prime }$ expansion. We also discuss the unoriented Type IIB theory on $T^6/{\mathbb{Z}}_2\times {\mathbb{Z}}_2$ where two-point string scattering amplitudes of the complex Kähler moduli and complex structures of the untwisted sector are computed on the disk and projective plane. New results are obtained together with known ones. Finally, we compare string scattering amplitudes results at ${{\alpha }^{\prime }}^2$-order with the (curvature)² terms in the low energy effective action of D-branes and Ω-planes in both cases.

我们重新考虑了在磁盘和投影平面上IIB型Orientifold超弦理论的无质量Neveu-Schwarz–Neveu-Schwarz状态的两点弦散射振幅在十维上的分布并对其进行了分析 ${\alpha }^{\prime }$扩张。我们还将讨论无方向性的IIB型理论${Ť}^6/{\mathbb{ž}}_2\times {\mathbb{ž}}_2$其中在盘和投影平面上计算复Kähler模量和非扭转扇形的复杂结构的两点字符串散射幅度。与已知结果一起获得新结果。最后，我们比较了字符串散射幅度结果${{\alpha }^{\prime }}^2$在两种情况下，D形和Ω平面的低能量有效作用中具有（曲率）²项的-阶。