  We present a study of Higgs boson production in vector boson fusion and in
association with a vector boson and its decay to two vector bosons, with a
focus on the treatment of virtual loops and virtual photons. Our analysis is
performed with the JHU generator framework. Comparisons are made to several
other frameworks, and the results are expressed in terms of an effective field
theory. New features of this study include a proposal on how to handle
singularities involving Higgs boson decays to light fermions via photons,
calculation of the partial Higgs boson width in the presence of anomalous
couplings to photons, a comparison of the next-to-leading-order electroweak
corrections to effects from effective couplings, and phenomenological
observations regarding the special role of intermediate photons in analysis of
LHC data in the effective field theory framework. Some of these features are
illustrated with projections for experimental measurements with the full LHC
and HL-LHC datasets.
