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arXiv · 1612.00777

Fermion scattering amplitudes from gauge-invariant actions for open superstring field theory

Hiroshi Kunitomo·Yuji Okawa·Hiroki Sukeno·Tomoyuki Takezaki
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Abstract

We calculate on-shell scattering amplitudes involving fermions at the tree level in open superstring field theory. We confirm that four-point and five-point amplitudes in the world-sheet path integral with the standard prescription using picture-changing operators are reproduced. For the four-point amplitudes, we find that the quartic interaction required by gauge invariance adjusts the different assignment of picture-changing operators in the $s$-channel and in the $t$-channel of Feynman diagrams with two cubic vertices. For the five-point amplitudes, the correct amplitudes are reproduced in a more intricate way via the quartic and quintic interactions. Our calculations can be interpreted as those for a complete action with a constraint on the Ramond sector or as those for the covariant formulation developed by Sen with spurious free fields.

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Hiroshi Kunitomo, Yuji Okawa, Hiroki Sukeno, Tomoyuki Takezaki. 2016-12-02. Fermion scattering amplitudes from gauge-invariant actions for open superstring field theory. https://arxiv.org/abs/1612.00777

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