Is Graviton A Zero Mass Particle?

Is Graviton A Zero Mass Particle? (The graviton, a gauge boson associated with gravity, is also expected be massless, but its existence hasn’t been confirmed yet.) These massless particles What is the mass of a graviton? Composition Elementary particle Antiparticle Self Theorized 1930s The name is attributed to Dmitrii Blokhintsev and F. M. Gal’perin in