Note on tree NLSM amplitudes and soft theorems
High Energy Physics - Theory
2026-05-05 v1
Abstract
We use the universality of single soft behavior, together with the double copy structure, to completely determine the tree amplitudes of non-linear sigma model (NLSM). We first figure out the Adler's zero for -point NLSM amplitudes, by considering kinematics. Then, we assume the universality of the Adler's zero, and use this requirement to construct general tree NLSM amplitudes in the expanded formula, i.e., the formula of expanding NLSM amplitudes to bi-adjoint scalar amplitudes. We also derive double soft factors for tree NLSM amplitudes, based on the resulting expanded formula.
Keywords
Cite
@article{arxiv.2306.09733,
title = {Note on tree NLSM amplitudes and soft theorems},
author = {Kang Zhou and Fang-Stars Wei},
journal= {arXiv preprint arXiv:2306.09733},
year = {2026}
}
Comments
26 pages, 10 figures. arXiv admin note: text overlap with arXiv:2212.12892