Inclusion of the $^3P_0$ model in PYTHIA 8

TL;DR

This paper integrates the $^3P_0$ model into PYTHIA 8 to simulate spin effects in hadronization, specifically for pseudo-scalar mesons, and demonstrates preliminary results on asymmetries in polarized scattering.

Contribution

The paper introduces the first implementation of the $^3P_0$ model's spin effects into PYTHIA 8, enabling more detailed simulations of polarized hadronization processes.

Findings

Preliminary simulation results on Collins asymmetries.

Implementation of the $^3P_0$ model interface in PYTHIA 8.

Initial insights into di-hadron asymmetries in polarized scattering.

Abstract

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 $^3P_0$ model. The interface between PYTHIA 8 and the package of the $^3P_0$ model is presented together with preliminary results on the Collins and di-hadron asymmetries as obtained from simulations of the transversely polarized semi-inclusive deep inelastic scattering process.