Angular analysis of B -> J/psi K1 : towards a model independent   determination of the photon polarization with B-> K1 gamma
  We propose a model independent extraction of the hadronic information needed to determine the photon polarization of the b-> s gamma process by the method utilizing the B -> K1 gamma -> K pi pi gamma angular distribution. We show that exactly the same hadronic information can be obtained by using the B -> J/psi K1 -> J/psi K pi pi channel, which leads to a much higher precision. 
E. Kou, A. Le Yaouanc and A. Tayduganov
hep-ph hep-ex