UPSILON spectroscopy

Using the CUSB detector, we have been doing spectral studies of the UPSILON system at CESR. Our early results included (i) the resolution of the third bound triplet spin state UPSILON''(10.32), whose transitions to P states we are presently engaged in, and (ii) the discovery of the quasibound UPSILON''(10.545) states which lies above open beauty threshold. Our recent results include (i) verification that the UPSILON decays into three gluons of spin 1; (ii) the absence of vibrational states and S-D mixing with GAMMAsub(ee)<0.03 KeV at 90% confidence level; (iii) the observation of ΔR (0.31 +- 0.06) across the flavor threshold; (iv) the measurement of branching fractions of hadronic intratransitions, confirming a QCD multipole expansion and that the gluon spin is 1; (v) the inference of E1 transition rates from topological analyses; and finally, (vi) the determination of the total and partial decay rates of the three bound triplet S states