CO(J=3-2) observations of MS 1512-cB58 at z=2.72

We report on a search for (CO)-C-12(J = 3-2) emission line toward MS 1512-cB58, a forming galaxy candidate at z = 2.72. We have observed the object with the 45-m telescope of the Nobeyama Radio Observatory, and found no significant emission. The 3 sigma upper limit of the CO (J = 3-2) line luminosity is 4.4 x 10(10) K km s(-1) pc(2), assuming a line velocity width of 300 km s(-1) this corresponds to a molecular hydrogen mass of 2.0 x 10(11)M(a), if we assume the Galactic CO-to-H-2 conversion factor. A lower limit on the ratio of the H alpha line luminosity to the CO luminosity of MS 1512-cB58 is at an upper part of, but within, the range of ratios for nearby galaxies.