GAUGE-GROUP-INVARIANT AND RENORMALIZATION-GROUP-INVARIANT FORMULATIONOF THE HIGGS-BOSON RESONANCE - ART. NO. 053002

A gauge- and renormalization-group-invariant approach implemented by t he pinch technique is formulated for resonant transitions involving th e Higgs boson. The line shape of the Higgs boson is shown to consist o f two distinct and physically meaningful contributions: a process-inde pendent resonant part and a process-dependent non-resonant background, which are separately gauge independent, invariant under the renormali zation group, satisfy naive, tree-level Ward identities, and respect t he optical and equivalence theorem individually. The former process-in dependent quantity serves as the natural extension of the concept of t he 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 tho se found with other methods is briefly discussed. [S0556-2821(98)07215 -4].