NUCLEAR-DEPENDENCE OF THE PRODUCTION OF GAMMA-RESONANCES AT 800 GEV

The yields of the 1S and the sum of the 2S and 3S Y resonances have been measured for 800-GeV protons incident on targets of H-2, C, Ca, Fe, and W. A significant nuclear dependence is seen in the yield per nucleon which, within errors, is the same for the Y(1S) and Y(2S + 3S) states. A large decrease in the relative yield from heavy nuclei is found for the range x(F) < 0. Significant nuclear dependence is also observed in the p(t) distribution. Differential cross sections for the Y(1S) for H-2 are presented over the ranges 0.24 less-than-or-equal-to p(t) less-than-or-equal-to 3.4 GeV/c and -0.15 less-than-or-equal-to x(F) less-than-or-equal-to 0.5.