get_polarized_squared_amplitude_rcl

get_polarized_squared_amplitude_rcl(npr, order, hel, pow=None, als=None)

Extracts a specific contribution to the polarized squared amplitude of the process with process number npr, according to the values of pow (or als), order, colour and hel.

Parameters:
  • npr (int) – process number
  • order (str) –

    loop-order of the contribution:

    • order = ‘LO’ : tree squared amplitude
    • order = ‘NLO’ : loop squared amplitude
    • order = ‘NLO-D4’: loop squared amplitude, bare loop contribution
    • order = ‘NLO-CT’: loop squared amplitude, counterterms contribution
    • order = ‘NLO-R2’: loop squared amplitude, rational terms contribution
    • order = ‘NLO-IR1’: loop squared amplitude, IR single pole contribution
  • hel (int[l]) –

    helicity (array) with entries:

    • left-handed fermions/antifermions: -1
    • right-handed fermions/antifermions: +1
    • logitudinal vector bosons: 0
    • transverse vector bosons: -1, +1
    • scalar particles: 0
  • pow/gs (int[]) – array with values representing the powers in fundamental couplings in the order as dictated by the model file, e.g. [2, 3] \(\equiv g_\mathrm{s}^2 e^3\), or, if supported by the model, the power in terms of \(g_\mathrm{s}\) only (power in \(e\) is determined automatically from the underlying process)
Returns:

A2

Return type:

(float)