Is there any particle that can travel in greater speed than light?

Answer 1

A tachyon is a hypothetical subatomic particle that moves faster than light. In the language of special relativity, a tachyon would be a particle with space-like four-momentum and imaginary proper time. A tachyon would be constrained to the space-like portion of the energy-momentum graph. Therefore, it cannot slow down to subluminal (slower than light) speeds.

Despite the theoretical arguments against the existence of tachyon particles, experimental searches have been conducted to test the assumption against their existence; however, no experimental evidence for the existence of tachyon particles has been found. Recently, time of flight measurements from the CERN-Opera collaboration have indicated that muon neutrinos may exceed the speed of light, but OPERA scientists have refrained from drawing conclusions, requesting that other groups first verify their result.