Equation Icon  τ [ 2 ] [hττ]H = 4ε4P-2 + ε6 − 2 m2-{(⃗n ⋅⃗v )2 − v2} − 16m1m2-- + 7m-2 + 𝒪 (ε7) (155 ) 1 r12 r12 12 2 2 r212 r212