Observation of Thirteen New Exclusive Multi-Body Hadronic Decays of the psi(2S)

Using data accumulated with the CLEO detector corresponding to an integrated luminosity of 5.63 pb^-1 on the peak of the psi(2S) and 20.70 pb^-1 continuum at 3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the psi(2S): eta 3pi, eta^\prime 3pi, rho K^+K^-, K^+K^-pi^+pi^-pi^0, 2(K^+K^-), 2(K^+K^-)pi^0, rho p \bar p, p \bar p pi^+pi^-pi^0, eta p \bar p, p \bar p K^+K^-, Lambda \bar Lambda pi^+pi^-, Lambda \bar p K^+, Lambda \bar p K^+pi^+pi^-, and more precise measurements of 8 previously measured modes: 2(pi^+pi^-), rho pi^+pi^-, 2(pi^+pi^-)pi^0, omega pi^+pi^-, K^+K^-pi^+pi^-, omega K^+K^-, phi K^+K^-, p \bar p pi^+pi^-. We also report new branching fraction measurements of phi pi^+pi^- and omega p \bar p and upper limits for eta pi^+pi^-, eta K^+K^- and phi p \bar p. Results are compared, where possible, with the corresponding J/psi branching ratios to provide new tests of the 12% rule.