The Photino Induced Distortion of the CMBR Blackbody Spectrum
  It is shown that photon--photino inter-conversions (if exist) may result in a detectable CMBR spectrum distortion which amplitude depends on photino properties, such as its mass. An upper bound on the distortion parameter determined from the recent COBE-FIRAS data, hence, sets a lower bound on the photino mass, $m_{\tilde\gamma} \gtrsim 300 eV$. 
M.V. Medvedev