Inclusion of the 3P0 model in PYTHIA 8
The spin effects in the hadronization process have been included for the first time in the PYTHIA 8 event generator. The spin effects are limited to the production of pseudo-scalar mesons and are obtained from the propagation of the quark polarization along the fragmentation chain according to the rules of the so-called 3P0 model. The interface between PYTHIA 8 and the package of the 3P0 model is