Gravitino

The gravitino is a hypothetical elementary particles. In models that extend the standard model to general relativity and supersymmetry, the gravitino the supersymmetric partner of the graviton also hypothetical.

The gravitino is a fermion with spin 3/2, its mass is either in the range keV / c ² or TeV / c ²; for comparison, the mass of the proton is 0.94 GeV / c ². In the second case, the gravitino plays only a role for cosmological observations, especially for the baryogenesis. In the case of a light gravitino ( keV / c ²) but can also measurable particle physics processes exist (see following chapter ).

Light gravitino

Or all - - ​​If the gravitino is the lightest supersymmetric elementary particles ( LSP) and the R - parity ( almost ) is retained, many can supersymmetric particles with appreciable width decay in their standard model superpartner and a gravitino, which opens up different possibilities:

• The decays into a gravitino could be detected in future particle accelerators. This can be done by decay inside the detector in the case of short lifetimes of the super affiliates. In the case of longer lifetimes, there is the idea to stop charginos outside of the detector, to make them fall apart there. In principle, the gravitino can be generated directly in particle collisions, for which often a Monojet signal is expected ( an energy deposition in only one region of the detector and a lack of energy due to the undetected gravitino ). The probability for such a production decreases with increasing mass of the gravitino, resulting in particle physics can lower limits for the Gravitinomasse specify.
• In most supersymmetric models the lightest neutralino is a candidate for dark matter, as many decays end in this particle; the Particle Data Group announced in 2006 as an experimental lower limit on its mass is 46 GeV / c ² to. A sufficiently light gravitino ( keV / c ²) could take over the role of the LSP and thus be a candidate for dark matter.