Diagram

class madspace.Diagram(self: madspace._madspace_py.Diagram, incoming_masses: collections.abc.Sequence[SupportsFloat], outgoing_masses: collections.abc.Sequence[SupportsFloat], propagators: collections.abc.Sequence[madspace._madspace_py.Propagator], vertices: collections.abc.Sequence[collections.abc.Sequence[madspace._madspace_py.LineRef]])

Bases: pybind11_object

A tree-level Feynman diagram: external masses, internal Propagator lines and the vertices connecting them.

Incoming and outgoing lines and propagators are each 0-indexed. A collision has two incoming lines, the beams 0 and 1; a decay has the single decaying particle as incoming line 0. A Diagram is turned into one or more Topology integration channels. PhaseSpaceMapping walks those to build the recursive phase-space decomposition (Sec. 2.2 of [1]).

References

Parameters:

  • incoming_masses – Masses of the incoming particles: the two beams of a collision, or the single decaying particle.

  • outgoing_masses – Masses of the outgoing particles.

  • propagators – The internal lines.

  • vertices – The vertices, each listing its LineRef lines.

property incoming_masses

Masses of the incoming particles.

property incoming_vertices

Index of the vertex each incoming line attaches to.

One entry per incoming particle: two for a collision, one for a decay.

property outgoing_masses

Masses of the outgoing particles.

property outgoing_vertices

Index of the vertex each outgoing line attaches to.

property propagator_vertices

For each propagator, the indices of its two end vertices.

property propagators

The internal propagator lines.

property vertices

The vertices.