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arXiv · 2604.00141

Manifest Moebius invariance of massive tree-level three-point amplitudes in pure spinor superspace

Chen Huang·Carlos R. Mafra·Yi-Xiao Tao
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Abstract

Using BRST cohomology properties in pure spinor superspace and identities for OPE brackets of non-free fields, we obtain a new compact nested-bracket representation of massive tree-level three-point open-string amplitudes in which Moebius invariance is manifest. Explicit superspace calculations for amplitudes with level-one massive states confirm this finding, and we derive new BRST recurrence relations among three-point numerators to extend the result to arbitrary mass levels. This provides a manifestly Moebius-invariant expression for massive three-point amplitudes in the pure spinor formalism.

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Chen Huang, Carlos R. Mafra, Yi-Xiao Tao. 2026-03-31. Manifest Moebius invariance of massive tree-level three-point amplitudes in pure spinor superspace. https://arxiv.org/abs/2604.00141

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