Superfield Approach to Symmetry Invariance in Qed with Complex Scalar Fields

We show that the Grassmannian independence of the super Lagrangian density, expressed in terms of the superfields defined on a (4, 2)-dimensional supermanifold, is a clear-cut proof for the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST invariance of the corresoponding four (3 + 1)-dimensional (4D) Lagrangian density that describes the interaction between the U(1) gauge field and the charged complex scalar fields. The above 4D field theoretical model is considered on a (4, 2)-dimensional supermanifold parametrized by the ordinary four spacetime variables x (with μ = 0, 1, 2, 3) and a pair of Grassmannian variables θ and θ̄ (with θ = θ̄ = 0, θθ̄ + θ̄θ = 0). Geometrically, the (anti-)BRST invariance is encoded in the translation of the super Lagrangian density along the Grassmannian directions of the above supermanifold such that the outcome of this shift operation is zero. PACS numbers: 11.15.-q; 12.20.-m; 03.70.+k