Do measurements of time-scales for decoherence disprove some versions of Copenhagen or MWI?
Since these discussions of interpretations of quantum mechanics often shed more heat than light, I want to state some clear definitions.
standard qm = linearity; observables are self-adjoint operators; wavefunction evolves unitarily; complete sets of observables exist
MWI-lite = synonym for standard qm
MWI-heavy = standard qm plus various statements about worlds and branching
CI = standard qm plus an additional axiom describing a nonunitary collapse process associated with observation
Many people who have formulated or espoused MWI-heavy or CI seem to have made statements that branching or collapse would be an instantaneous process. (Everett and von Neumann seem to have subscribed to this.) In this case, MWI-heavy and CI would be vulnerable to falsification if it could be proved that the relevant process was not instantaneous.
Decoherence makes specific predictions about time scales. Are there experiments verifying predictions of the time-scale for decoherence that could be interpreted as falsifying MWI-heavy and CI (or at least some versions thereof)?
I'm open to well-reasoned answers that cite recent work and argue, e.g., that MWI-heavy and MWI-lite are the same except for irrelevant verbal connotations, or that processes like branching and collapse are inherently unobservable and therefore statements about their instantaneous nature are not empirically testable. It seems possible to me that the instantaneousness is:
not empirically testable even in principle.
untestable for all practical purposes (FAPP).
testable, but only with technologies that date to ca. 1980 or later.
An example somewhat along these lines is an experiment by Lee at al. ("Generation of room-temperature entanglement in diamond with broadband pulses", can be found by googling) in which they put two macroscopic diamond crystals in an entangled state and then detected the entanglement (including phase) in 0.5 ps, which was shorter than the 7 ps decoherence time. This has been interpreted by Belli et al. as ruling out part of the parameter space for objective collapse models. If the coherence times were made longer (e.g., through the use of lower temperatures), then an experiment of this type could rule out the parameters of what is apparently the most popular viable version of this type of theory, GRW. Although this question isn't about objective collapse models, this is the same sort of general thing I'm interested in: using decoherence time-scales to rule out interpretations of quantum mechanics.