Gravitino

In supergravity theories combining general relativity and supersymmetry, the gravitino (G͂) is the gauge fermion supersymmetric partner of the hypothesized graviton.

[1][2] The current name of gravitino was instead suggested by Sidney Coleman and Heinz Pagels,[3] although this term was originally coined in 1954 by Felix Pirani to describe a class of negative energy excitations with zero rest mass.

[4] If the gravitino indeed has a mass of the order of TeV, then it creates a problem in the standard model of cosmology, at least naïvely.

At least one possible channel of decay must include either a photon, a charged lepton or a meson, each of which would be energetic enough to destroy a nucleus if it strikes one.

This causes almost all supersymmetric particles in the early Universe to decay into Standard Model particles via R-parity violating interactions well before the synthesis of primordial nuclei; a small fraction however decay into gravitinos, whose half-life is orders of magnitude greater than the age of the Universe due to the suppression of the decay rate by the Planck scale and the small R-parity violating couplings.