  Angular correlations arising from particle-particle (pp) propagation in
nuclear matter are investigated. Their account follows an exact treatment of
the Pauli exclusion principle on intermediate states in the
Bruekner-Bethe-Goldstone (BBG) equation. As a result, a correlation form factor
emerges from the Cauchy principal-value of the pp propagator, while the
imaginary part becomes structurally different from those in
Lippmann-Schwinger-type equations. These novel features modify drastically the
behaviour of the mass operator near the Fermi surface, reshaping the
phase-space where its imaginary part vanishes and sliding down the saturation
point of symmetric nuclear matter along the Coester band. The correlation
structures found here --which go beyond angle-averaged (or effective-mass type)
energy denominators-- may impact present day model predictions for neutron
stars based on the BBG equation, and for scattering and reaction observables in
full folding optical model calculations
