Study of pi + pi - transitions from the Upsilon (3S) and a search for the hb.

We have investigated the transitions Y(3S)~m+vr Y(1S), Y(3S)~~+~ Y(2S) and the cascade process Y(3S)~Y(2S)+X,Y(2S)~m+w Y(1S), both in the exclusive decay mode, with the daughter Y state decaying into two leptons, and in the inclusive decay mode, with the daughter Y state decaying hadronically. Results are presented on the branching fractions and properties of the system. The m+ ~ invariant-mass spectra for the decays Y( 3S)~~+ m Y( 1S) and Y(3S)~m ~ Y(2S) are measured and compared with theoretical predictions. We also present the results of a search for the h&(1 'P, ) and Y(1 'D) states in inclusive Y(3S) decays, and for the ex