Graviton & Gravitino
In theoretical physics, M-theory is a proposed unified theory that aims to incorporate various versions of string theory. It is an extension of superstring theory that involves higher-dimensional objects called branes. M-theory is still an area of active research, and many aspects of it are not yet fully understood. However, I can provide you with some information regarding gravitons and gravitinos in the context of M-theory.
Gravitons:
In quantum field theory, gravitons are hypothetical elementary particles that mediate the force of gravity. According to M-theory, gravity arises from the interactions of closed strings, and the exchange of gravitons between these strings gives rise to the gravitational force. Gravitons are considered to be massless particles with a spin of 2, which means they are associated with the gravitational field and carry two units of angular momentum.
Gravitinos:
Gravitinos, on the other hand, are hypothetical supersymmetric partners of gravitons. Supersymmetry is a theoretical framework that suggests the existence of a symmetry between fermions (particles with half-integer spin) and bosons (particles with integer spin). Gravitinos are fermionic particles with a spin of 3/2, making them the supersymmetric counterparts of the graviton.
In M-theory, the existence of gravitinos is predicted due to its supersymmetric nature. Gravitinos are associated with the supersymmetric version of gravity and play a role in supergravity theories, which are extensions of general relativity that incorporate supersymmetry. Gravitinos, if they exist, would interact with other particles through gravitational interactions and also through their supersymmetric partners, such as quarks, leptons, and gauge bosons.
It's important to note that M-theory is still a subject of ongoing research, and many of its details are yet to be fully understood. The precise nature of gravitons and gravitinos within M-theory, as well as their experimental confirmation, remain active areas of investigation for theoretical physicists.