As far as I know, according to quantum field theory, there are some photons that go faster than c, which is the speed of light in vacuum.
However, there seems to be a paper and a corresponding experiment that show every photon obeys the speed limit of c. (http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.243602)
So, my question is:
Is this experiment accepted universally?
Regardless of the acceptance of the experiment, if every single photon is shown to obey the speed limit of c, what does this mean for quantum field theory?