We use the infrared consistency of one-loop amplitudes in N = 4 Yang-Mills theory to derive a compact analytic formula for a tree-level next-to-next-to-maximal helicity-violating gluon scattering amplitude in QCD, the first such formula known. We argue that the infrared conditions, coupled with recent advances in calculating one-loop box coefficients, can give a new tool for computing tree-leve...

We identify a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes, without any ambiguities. One-loop amplitudes for massless supersymmetric gauge theories fall into this class; in addition, many non-supersymmetric amplitudes can be rearranged to take advantage of the result. As applications, we construct the one-loop amplitudes fo...

The Ward identities for amplitudes at the tree level are derived from symmetries of the corresponding classical dynamical systems. The result are aplied to some 2 → n amplitudes supported by the Lódź University grant No. 269. supported by KBN grant No. 5 P03B 060 21 1 I Introducion Threshold amplitudes provide one of the rare examples of problems in quantum field theory which are both interesti...

We explore how various topics in modern scattering amplitudes research find application the description of collider physics processes. After a brief review experimentally measured quantities and they are related to amplitudes, we summarise recent developments perturbative QFT, have impacted our ability do precision with colliders. Next, explain study (next-to-)soft radiation is directly relevan...

We formulate the field-space geometry for an effective field theory of scalars and gauge bosons. Geometric invariants such as curvature enter in both scattering amplitudes renormalization group equations, with scalar results unified a single expression.