English

Some tree-level string amplitudes in the NSR formalism

High Energy Physics - Theory 2016-08-22 v4

Abstract

We calculate tree level scattering amplitudes for open strings using the NSR formalism. We present a streamlined symmetry-based and pedagogical approach to the computations, which we first develop by checking two-, three-, and four-point functions involving bosons and fermions. We calculate the five-point amplitude for massless gluons and find agreement with an earlier result by Brandt, Machado and Medina. We then compute the five-point amplitudes involving two and four fermions respectively, the general form of which has not been previously obtained in the NSR formalism. The results nicely confirm expectations from the supersymmetric F4F^4 effective action. Finally we use the prescription of Kawai, Lewellen and Tye (KLT) to compute the amplitudes for the closed string sector.

Keywords

Cite

@article{arxiv.1507.02172,
  title  = {Some tree-level string amplitudes in the NSR formalism},
  author = {Katrin Becker and Melanie Becker and Ilarion V. Melnikov and Daniel Robbins and Andrew B. Royston},
  journal= {arXiv preprint arXiv:1507.02172},
  year   = {2016}
}

Comments

40+8 pages; v2: references added; v3: additional field theory checks made; published version; v4: minor corrections; results unchanged

R2 v1 2026-06-22T10:08:03.842Z