Towards the experimental clarification of quarkonium polarization Pietro Faccioli, Carlos Lourenço, João Seixas and HermineK. Wöhri Eur. Phys. J. C, 69 3-4 (2010) 657-673 Published online: 01 September 2010 DOI: 10.1140/epjc/s10052-010-1420-5