  A gauge- and renormalization-group- invariant approach implemented by the
pinch technique is formulated for resonant transitions involving the Higgs
boson. The lineshape of the Higgs boson is shown to consist of two distinct and
physically meaningful contributions: a process-independent resonant part and a
process-dependent non-resonant background, which are separately gauge
independent, invariant under the renormalization group, satisfy naive,
tree-level Ward identities, and respect the optical and equivalence theorem
individually. The former process-independent quantity serves as the natural
extension of the concept of the effective charge to the case of the Higgs
scalar, and constitutes a common ingredient of every Born-improved amplitude.
The difference in the phenomenological predictions obtained within our approach
and those found with other methods is briefly discussed.
