A Study on Delta-u and Delta-d in charged current events using polarized beams at HERA

Charged current events are studied at HERA with polarized beams, using a Monte Carlo event generator and taking into account detector smearing effects. The observed asymmetries are used to study the extraction of the polarized structure function g_5 and the polarized parton distributions $\Delta u$ and $\Delta d$ in the proton.