Recursive model for the fragmentation of polarized quarks

Understand

We present a model for Monte Carlo simulation of the fragmentation of a polarized quark.

• The model is based on string dynamics and the ${}^3P_0$ mechanism of quark pair creation at string breaking.
• The fragmentation is treated as a recursive process, where the splitting function of the subprocess $q \to h + q'$ depends on the spin density matrix of the quark $q$.
• The ${}^3P_0$ mechanism is parametrized by a complex mass parameter $\mu$, the imaginary part of which is responsible for single spin asymmetries.