compute_process_rcl

compute_process_rcl(npr, p, order)

Computes the structure-dressed helicity amplitudes and the summed squared amplitude (unless polarizations specified, see define_process_rcl()) for the process with process number npr.

Parameters:
  • npr (int) – process number
  • p (float[l][4]) – external momenta of the process with l legs
  • order (str) – loop order, accepted values are 'LO' and 'NLO'
Returns:

(\(|A_0|^2\), \(2 \mathrm{Re}[A_0 A_1]\), momenta_check)

Return type:

(float, float, bool)

momenta_check tells whether the phase-space point is good (momenta_check=True) or bad (momenta_check=False) one. In the latter case no computation is performed and zero is returned for the matrix elements.

Note

If the process is loop-induced, instead of \(2 \mathrm{Re}[A_0 A_1]\) the squared loop \(|A_1|^2\) is returned.