The belief is not enough in physic and it's always superseded by understanding. To decide such question you should understand at first, what's the wave function at all. It has no sense to dispute the existence of object, which has no physical meaning for you - such object remains solely abstract and such question has no meaning at all.

By AWT the observable Universe can be described by the waves of massive elastic environment (i.e. Aether), whose density is proportional the total energy density of waves in given place and location. Despite the fact, you believe in Aether or not, the E=mc^2 law should remain valid inside our generation of Universe.

By such way, each the wave is moving through Aether in certain dense energy blob, making the Aether more dense at the same place. If the energy density is large enough, the lensing effect of such blob focuses the energy wave into closed wave pocket. By such way, the virtual particle (boson) changes to the real particle with non zero rest mass (the energy "is materialized"). And the wave function is simply the energy profile of the resulting wave pocket. You can check this point on the simple DHTML applet here (just for MSIE, till now).

It should be point out, the energy wave envelope doesn't depend on the wave phase inside the wave pocket, i.e. multiple waves with the very same wave function can have quite different phase in it - from this point follows the probabilistic character of quantum mechanic. Such indeterminism goes quite deep: if the count of particles exceed the probability of appearance of the same phase inside the different particles, a spontaneous phase transition occurs. By such way, the Universe keeps all the particles in the same space-time unit a truly unique.



The virtual particles commonly appears in pairs (so called Cooper pairs) due the symmetry of torsion vibrations inside foam, which is forming the Aether. By such way, the formation of virtual particles is pretty similar to the formation of multidimensional fractal vortices, similar to those, which are observable at the water surface (see the large picture above).

From the above follows, the virtual particles are having normal wave function like common particles - they're just heavily entangled, i.e. they're sharing the same phase inside their wave pockets, so they can be created (materialized) and annihilated again without directly observable effects (see the animation on the right).