There is a particle for gravity, it's the graviton (massless, spin-2). It is not observed experimentally because it's extremely far from our technological capabilities.
In fact, mathematically, General Relativity can be understood as the classical field theory of a massless, self-interacting, spin-2 field. In the same way that electromagnetism is the classical field theory of a massless, non-interacting, spin-1 field.
In fact, mathematically, General Relativity can be understood as the classical field theory of a massless, self-interacting, spin-2 field. In the same way that electromagnetism is the classical field theory of a massless, non-interacting, spin-1 field.