Decay12_BeforeBoost_Lab

O = (0, 0)
A = (5.432011898443491, -1.2341762537076946, 2.2404)
p_{a} = Vector((0, 0, 0), A)
p_2 = Vector((0, 0, 0), (-2, -3, 2))
p_1 = Vector((0, 0, 0), (1, 2, 3))
p_{12}: p_1 + p_2
u: p_1 ⊗ p_2
decayplane = OrthogonalPlane((0, 0, 0), Vector[p_1 ⊗ p_{12}])
θ_2 = Angle(p_2, Vector[(0, 0, 1)])
ϕ_{1old} = Angle(y = 0, decayplane)
v: p_1 ⊗ p_2
productionplane = OrthogonalPlane(O, Vector[p_{a} ⊗ p_{12}])
ϕ_{1} = Angle(decayplane, productionplane)
p_{3}: (-p_{12})
θ_1 = Angle(p_1, p_{12})
p_{b}: (-p_{a})