compute_spin_correlation_matrix_rcl(npr, p, j, order='LO')

Computes the summed spin-correlated matrix squared amplitude \(B_j^{\mu\nu}\) (arXiv:1002.2581 Eq. (2.8)) for the vector particle j (a gluon or photon).

  • npr (int) – process number
  • p (float[l][4]) –
  • j (int) – photon/gluon leg
  • order (str) – loop-order, accepted values ’LO’ and ’NLO’
  • 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)

(A2scm, momcheck)

Return type:

(float, bool)