Various effects which could perhaps create the
illusion of superluminal motion in neutrinos. In alphabetical order.
- Changes in Composition or Strength of Beam as it Travels:
- Coherent Neutrinos:
- Complementary Special Relativity: A theory which disagrees
with standard special-relativity, but also (according to the
paper below) gives v = c in the OPERA experiment.
- Dark Matter:
- Flavour-Oscillation Effects:
- Gravitational Effects:
- Phase-Velocity, Group-Velocity, and Wave-Packet Effects:
Phase velocities, of course, can exceed the speed of light. So (under particular circumstances)
can group velocities. In neither case, however, is information actually
transmitted, so Lorentz invariance survives. Broadening of a wave-packet
(as would happen, for example, if its component waves move at different
speeds) can also make it difficult to recognise whether a "velocity"
associated with the packet is physically meaningful. Therefore, experimenters
need to be careful about what they are measuring.
- Quantum Fields:
Virtual Speed of Neutrino
by Arnab Shome
[2012/01] Argues qualitatively that annihilation events in vacuum
change length of path traversed.
- Quantum Weak-Measurement:
- Reference-Frame Effects:
- Temperature Should Be Included in the Relativistic Velocity-Formula:
- Time Delay is a More Complicated Idea Than One Might Think: