Cherenkov Radiation Credit: Wikipedia
A recent criticism of the apparently Faster-than-light (FTL) Neutrinos inspiring a lot of discussion is the claim that if Neutrinos are going FTL – they must cause Cherenkov radiation.
Why? That doesn’t make sense. And its never been observed so how would anyone test that?
Cherenkov Radiation Requires Charged Particles – But Neutrinos Have No Charge
The beautiful blue-violet glow of Cherenkov Radiation is only caused by charged particles, primarily electrons.
But Neutrinos are neutral, they have no charge. Furthermore, because they are fundamental particles; they don’t have any electrons.
Commentary: Since Neutrinos have never been observed directly making Cherenkov Radiation – why should anyone imagine they should?
Yes, Neutrinos are commonly detected by observing Cherenkov Radiation, but indirectly – not directly. That extremely rare Cherenkov Radiation detection glow is not from a Neutrino – it comes from an Electron. It occurs in the extremely rare event of a Neutrino hitting an Electron head-on.
This particular suggestion does not seem to hold water.
However, you might want to read why Matt Strassler disagrees. He bases this on the existence of a Neutrino non-zero magnetic moment. My response is that no Neutrino magnetic moment has ever been observed either; it is only postulated.
I do remain concerned that the OPERA experiment is only Detecting Only 1 Neutrino per Hour.
References:
New Constraints on Neutrino Velocities
Cherenkov radiation From Wikipedia
they are projected to produce c radiation when traveling through matter not vacuum. I guess it would have to be extremely pressurized or extremely magnetic or both.
Thank you for your thought Kate.
Can you help offer an explanation why it would make any difference if Neutrinos were going through highly charged matter, extremely dense matter or a vacuum.
Neutrinos are still neutral and they don’t have any electrons – so they don’t interact with matter – even extremely highly charged matter — unless they hit a quark or an electron head on (or graze by allowing their breathtakingly miniscule gravity or their weak force to affect the other particle).
That would be a exquisitely rare event, not a typical (or common) occurrence that is required by the FTL Cherenkov radiation hypothesis.