Fine Structure of the Upsilon 2p States.

The Columbia-Stony Brook (CUSB) collaboration has measured the photon spectrum resulting from the decays Upsilon (3S)togamma + hadrons using the CUSB-II BGO calorimeter. The spectrum contains the signal from the electromagnetic transitions Upsilon (3S)togammachi _{b,J=0,1,2} (2P). From this signal the masses of the chi_{b}(2P) states were determined to be 10268.0 +/- 0.8, 10255.4 +/- 0.8, and 10233.9 +/- 1.2 MeV for the J = 2, 1, and 0 states respectively. The ratio of the mass splittings, (M_{chi _{b2}} - M_{chi_{b1}} )/(M_{chi_{b1 }} - M_ {chi_{b0}}) imply that the long range confining piece of the inter-quark potential transforms as a Lorentz scalar.