We present a measurement of the polarization observed for bottomonium states produced in collisions at . The angular distribution of the decay dimuons of the state shows no polarization at small values of the fractional longitudinal momentum and transverse momentum but significant positive transverse production polarization for either or for . The (unresolved) states show a large transverse production polarization at all values of and measured. These observations challenge NRQCD calculations of the polarization expected in the hadronic production of bottomonium states.
- Received 7 November 2000
- Published in the issue dated 19 March 2001
© 2001 The American Physical Society