POLDIS A Monte Carlo for POLarized (semi-inclusive) Deep Inelastic Scattering Original Research Article

POLDIS is a Monte Carlo program for polarized (semi-inclusive) deep inelastic scattering (DIS). Unpolarized DIS events are generated with the existing lepto-production event generators LEPTO for DIS and AROMA for Heavy Flavor production. The relevant spin asymmetries are computed at partonic level to first order in αs for each generated event, and are then convoluted with the corresponding parton polarization. This procedure provides a polarization weight for each event. The average of these polarization weights gives the polarized cross section spin-asymmetry for the generated sample. The code consists of a set of subroutines to be linked with LEPTO and/or AROMA. No modification to these programs is required. Some existing polarized parton distribution functions are also included.