Should a neutrino be moving slightly slower than c?

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The ICARUS results indicate that neutrinos travel at the speed of light, c, contradicting earlier CERN findings attributed to equipment errors. There is a discussion about whether neutrinos should move slightly slower than c due to their mass, but the difference may be negligible and undetectable with current technology. Historical data from supernova SN1987A shows neutrinos arriving just three hours before light, suggesting they travel extremely close to c. The MSW effect implies neutrinos have mass, but the mass eigenstate could potentially be zero, complicating the understanding of their speed. Overall, the consensus leans towards neutrinos moving at c, with any variations being too small to measure accurately.
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The ICARUS results evidence that neutrino moves at speed, not faster/slower, but same as c.
The CERN results seem to be wrong due to some error in the equipment.

http://arxiv.org/ftp/arxiv/papers/1203/1203.3433.pdf

aren't the neutrinos expected to travel slightly slower than c? (due to slight mass)

or is the mass (velocity) difference too small to be noticeable, by any experiment?

c = speed of light/photon

the photon has zero rest mass. i am assuming that the relativistic mass of the photon is less than that of neutrino.
 
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The MSW effect says that neutrinos have (some) mass...except there's the loop hole that 1 mass eigenstate of the neutrinos could be 0, so there's that. There are some upper bounds on neutrino masses, but they seem to be extremely extremely light.

Neutrinos from SN1987A showed that they basically kept their 3 hour head start on the photons over a distance of ~160k light years! This means they travel EXTREMELY close to the speed of light.

EDIT: I typo'd I should have said 1 mass eigenstate "COULD BE" 0. The MSW effect doesn't say that any of them has to be 0. It does say that not all of them can be 0, however.
 
You're right, they should. But as you say the difference may be incredibly small, especially if you consider that neutrinos from the 1987 supernova arrived at about the same time as light did (apart from the three hour difference which was due to other factors). So my guess is that the slight lag in speed for the neutrinos may be too small to measure with our current technology.

(BTW, shouldn't this question go into the other neutrino thread?)
 
lmoh said:
(BTW, shouldn't this question go into the other neutrino thread?)

Where it's already been answered in posts 750 and 751...
 
In this video I can see a person walking around lines of curvature on a sphere with an arrow strapped to his waist. His task is to keep the arrow pointed in the same direction How does he do this ? Does he use a reference point like the stars? (that only move very slowly) If that is how he keeps the arrow pointing in the same direction, is that equivalent to saying that he orients the arrow wrt the 3d space that the sphere is embedded in? So ,although one refers to intrinsic curvature...

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