Polarization Measurements of the Recoil Proton in $H(\vec{\gamma},\vec{p})\pi^0$ reaction

Perturbative QCD theory predicts that the polarization components of the proton above the baryon resonance region should have a smooth dependence of $E_{\gamma}$, and approach limits established by hadron helicity conservation in the $H(\vec{\gamma},\vec{p})\pi^0$ reaction. Published data shows strong variation of the polarization variables above $2 \mbox{ GeV}$, which could be a sign of high-mass resonances. We present preliminary results for the $\pi^{0}$ photo-production from Jefferson Lab Hall C experiments E04-108, E04-019, E07-002 and Hall A experiment E99-114, which all measured the polarization observables of the recoil proton with high statistics. Our data extends the polarization measurements of $\pi^{0}$ photo-production up to $E_{\gamma}=5.7 \mbox{ GeV}$, with four momentum transfers up to 8.5 GeV$^2$. The results show consistency with published data up to $4.1 \mbox{ GeV}$. We will discuss the interpretation of these results.