Search for an Anomalously Heavy Isotope of Oxygen

Abstract

A search has been made for an anomalously heavy isotope of oxygen spanning the mass range 20 to 54 amu with use of a tandem accelerator as an ultrasensitive mass spectrometer. An upper limit of heavy hadron to nucleon ratios was established at ${10}^{\ensuremath{-}16}$ over the entire mass region and over a large portion of it at ${10}^{\ensuremath{-}18}$. This ratio is considerably lower than the predictions of cosmological models, namely \ensuremath{\sim}${10}^{\ensuremath{-}10}$ to ${10}^{\ensuremath{-}11}$.