Worldsheet Portability in Fixed-Point String Theory: Hadronic Vacuum Polarization Across Electroweak Observables

Portability of a hadronic vacuum polarization (HVP) worldsheet derived in fixed-point Type IIB string compactification is investigated across electroweak and collider observables. The worldsheet construction yields a geometric suppression factor R = 0.967 associated with path length λ = 6. The portability hypothesis is that the worldsheet encodes an intrinsic property of the electromagnetic hadronic current correlator and therefore damps physical HVP insertions independently of the external observable that probes them. Direct portability tests are identified in dispersive–lattice HVP comparisons and in energy-resolved R-ratio normalization. Consequences for observables sensitive to the hadronic contribution to the running electromagnetic coupling, ∆αhad(Q^2), are organized as propagated implications contingent on the scale and kernel dependence of the suppression, parameterized by an observable-dependent effective factor RO . Electroweak-fit quantities several steps removed from HVP are presented as estimates pending verification of scale behavior and fit sensitivities. Structured falsification criteria are provided to distinguish a universal portable suppression from kernel-dependent portability limits.