单负胶子树图振幅非零

Single-minus gluon tree amplitudes are nonzero

February 12, 2026

作者: Alfredo Guevara, Alexandru Lupsasca, David Skinner, Andrew Strominger, Kevin Weil

cs.AI

摘要

本文重新审视了单负号树阶n胶子散射振幅。尽管通常被认为为零，但我们证明在克莱因空间存在的特定"半共线"构型或复数化动量情况下，这些振幅并不消失。我们推导出了单个负螺旋度胶子衰变为n-1个正螺旋度胶子的分段常数闭式表达式，该公式是粒子动量的函数。这一表达式非平凡地满足了包括温伯格软定理在内的多重自洽条件。

English

Single-minus tree-level n-gluon scattering amplitudes are reconsidered. Often presumed to vanish, they are shown here to be nonvanishing for certain "half-collinear" configurations existing in Klein space or for complexified momenta. We derive a piecewise-constant closed-form expression for the decay of a single minus-helicity gluon into n-1 plus-helicity gluons as a function of their momenta. This formula nontrivially satisfies multiple consistency conditions including Weinberg's soft theorem.