Light Gluino Mass and Condensate from Properties of $\eta$ and $\eta'$
  We investigate whether known properties of the $\eta'$ meson are consistent with its being the Goldstone boson of the spontaneously broken anomaly-free R symmetry required in the light gluino scenario. We fit the masses and $2\gamma$ decays of the $\eta$ and $\eta'$ mesons, and also their production in radiative $J/\psi$ decays. We find that the $\eta-\eta'$ system is well-described in the light gluino scenario, if $m_\lambda\simeq (84-144) MeV$ and $<{\bar\lambda}\lambda> \simeq -(0.15-0.36) GeV^3$. These values are in the range expected when the gluino gets its mass entirely from radiative corrections. 
Glennys R. Farrar and G.T. Gabadadze (Rutgers Univ.)