# compute_spin_correlation_matrix_rcl¶

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).

Parameters: 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) (float, bool)