Left panels:  ⟨ γγ ⟩ (r) with fixed φ_r = π/6 as a function of r. Right panels: polar angle of  ⟨ γγ ⟩ (r) with fixed r = 20 as a function of φ_r. The black curves are the expected values while the dots are the results from numerical evaluation of 2D integral in (23). The  ⟨ κκ ⟩  used in the upper panels is  ⟨ κκ ⟩ (r) = 1/r and in the lower panels  ⟨ κκ ⟩ (r) = exp(−r²).