Off-diagonal helicity density matrix elements for vector mesons produced at LEP

@inproceedings{Anselmino1997OffdiagonalHD,
  title={Off-diagonal helicity density matrix elements for vector mesons produced at LEP},
  author={Mauro Anselmino and Massimo Bertini and Francesco Murgia and P. Quintairos},
  year={1997}
}
Final state qq̄ interactions may give origin to non zero values of the off-diagonal element ρ1,−1 of the helicity density matrix of vector mesons produced in e e annihilations, as confirmed by recent OPAL data on φ and D’s. Predictions are given for ρ1,−1 of several mesons produced at large z and small pT , i.e. collinear with the parent jet; the values obtained for φ and D are in agreement with data.