More than one ultimate speed and superluminal neutrinos

Abstract

It is suggested that recent superluminal neutrinos from the OPERA collaboration might indicate that there are other ultimate speeds than usual speed of light in our universe. The leptonic sector of the standard model (SM) is reformulated incorporating with new ultimate speeds. In minimal cases where there is another maximum speed $c'$ which equals to the speed of the OPERA neutrinos, new effects would appear at the level of ${\cal O}(10^{-5})$. Improved precisions for the electroweak observables would check the validity of this scenario.