  Known mechanisms for breaking of supersymmetry at the level of string theory
imply that at least one of the internal dimensions has a very large size.
Experimental detection of the associated light Kaluza-Klein (KK) excitations
would be a strong hint for the existence of string like elementary objects, as
no consistent field theory describing them is known. We restrict the discussion
to the Scherk-Schwarz mechanism in orbifold compactifications. For this case we
investigate the quantum number of the lightest predicted KK states.
