Returns the inter-particle Euclidean distances between particles internally within the given MomentumArray.

Parameters:¶

pmu : MomentumArray¶

Four-momenta of particle set.

Returns:¶

delta_R_matrix – Square symmetric matrix representing the Euclidean distance between every pair of particles in the eta-phi plane.

Return type:¶

ndarray[float64]

Notes

Infinite values may be encountered if particles are travelling parallel to the beam axis, ie. with infinite pseudorapidity.