Observation of three P states in the radiative decay of UPSILON(2S)

The inclusive photon spectrum in hadronic decays of the UPSILON(2S) is measured with the Crystal Ball detector at DORIS II. Four well separated photon lines, which are consistent with the decay hypothesis UPSILON(2S)..--> gamma..+ /sup 3/P/sub 2,1,0/ and /sup 3/P/sub 2,1/..--> gamma..+UPSILON(1S), are observed. The energies of the lines from the primary transitions are E/sub gamma1/ = 110.4 +- 0.8 +- 2.2 MeV, E/sub gamma2/ = 130.6 +- 0.8 +- 2.4 MeV and E/sub gamma3/ = 163.8 +- 1.6 +- 2.7 MeV; the branching fractions are (5.8 +- 0.7 +- 1.0)%, (6.5 +- 0.7 +- 1.2)%, and (3.6 +- 0.8 +- 0.9)%, respectively. The secondary transitions center at approx. =430 MeV with a combined branching fraction of (3.6 +- 0.7 +- 0.5)%.