The SAGEX review on scattering amplitudes Chapter 13: Post-Minkowskian expansion from scattering amplitudes

TASI Lectures on Scattering Amplitudes

Tree Scattering Amplitudes *

The spin-4/3 fractional superstring is characterized by a chiral algebra involving a spin-4/3 current on the world-sheet in addition to the energy-momentum tensor. These currents generate physical state conditions on the fractional superstring Fock space. Scattering amplitudes of these physical states are described which satisfy both spurious state decoupling and cyclic symmetry (duality). Exam...

Calculation of the Scattering Amplitudes

It is well known that the high order calculations of the observables within the perturbation theory has the serious difficulties (especially, if we take into account the polarization effects). Method of the direct calculation of amplitudes simplifies these calculations essentially. There is an even number (2N) of fermions in initial and final state for any reaction with Dirac particles. Therefo...

Scattering Amplitudes from Three-Particle Equations

We here use our non-perturbative, cluster decomposable relativistic scattering formalism to calculate photon-spinor scattering, including the related particle-antiparticle annihilation amplitude. We start from a three-body system in which the unitary pair interactions contain the kinematic possibility of single quantum exchange and the symmetry properties needed to identify and substitute antip...

High–energy scattering amplitudes in QCD: from Minkowskian to Euclidean space

The parton–parton scattering amplitude, at high squared energies s in the center of mass and small squared transferred momentum t (that is s → ∞ and |t| ≪ s, let us say |t| ≤ 1 GeV), can be described by the expectation value of two infinite Wilson lines, running along the classical trajectories of the two colliding particles [1–4]. Let us consider, for example, the case of the quark–quark scatt...