THE C CO RATIO IN B335 AND THE DECAYING DARK-MATTER NEUTRINO HYPOTHESIS/

(CO)-O-18 J = 2-1, (CO)-O-17 J = 2-1 and [C I] P-3(1)-P-3(0) emission from the dense cold cloud B335 has been observed and modelled in order to determine the C/CO ratio. The observed ratio is compared with a pr ediction by Tarafdar who assumes a mechanism in which the CO dissociat ion is caused by photons of energy similar to 13.8 eV. These were post ulated by Sciama to result from the decay of dark matter neutrinos. Ou r value for the C/CO ratio sets an upper limit to the strength of the neutrino decay dissociation process, thus providing a significant datu m for interstellar chemistry theory.