Measurement of Yfl Final States in Jf' Decay*

The decay mode I$' d m has been studied with the Mark II detector at SPEAR. New measurements of branching ratios for decays of the type 9’ --j Y-x, x+ 73 involving known X states are presented. The existence of a X state of mass near 3455 MeV/c2 produced in this decay chain is not confirmed, and the upper limit (907 0 confidence level) of the product of branching ratios is measured to be 0.13%. A new decay mode, $' + x0$, which violates isospin conservation is observed with branching ratio (0.15+0.06)%. (Submitted to Physical Review Letters) * Work supported primarily by the Department of Energy under contract numbers DE-ACOj-76-15 and W-7405-ENG-48. + California Institute of Technology, Pasadena, California 91125. * Harvard University, Cambridge, Massachusetts 02138. ++ Universitst Bonn, 7. R. Germany. ** CEN-Saclay, France. -2The y-@ final states produced in +'(3684) d ecays have previously been shown to arise from the two processes,