A photon, a neutrino (if it has zero rest mass) move at $c$ but what about charged particles? If the answer is no, is there a fundamental reason or just because of the radiation it emits?
Asked
Active
Viewed 197 times
1 Answers
2
It's not impossible in principle to have a charged particle with no mass, but there is no known particle that is both charged and massless. Consequently, all charged particles are required to travel at some speed less than $c$. Note, however, that electrons at LHC energies are so excited that they functionally are travelling at $c$, since their energies are in GeV, and their rest mass is half of a MeV. It is in fact common in many particle physics calculations to ignore the electron mass, since doing this introduces errors smaller than the dominant sources of error in the problem.
Zo the Relativist
- 42,237