Measurement of the recoil polarization in the p((e)over-right-arrow, e '(p)over-right-arrow)pi(0) reaction at the Delta(1232) resonance

The recoil proton polarization has been measured in the p((e) over right ar row, e(1)(p) over right arrow)pi (0) reaction in parallel kinematics around W = 1232 MeV, Q(2) = 0.121 (GeV/c)(2) and epsilon = 0.718 using the polari zed cw electron beam of the Mainz Microtron. All three proton polarization components, P-x/P-e = (-11.4 +/- 1.3 +/- 1.4)%, P-y = (-43.1 +/- 1.3 +/- 2. 2)%, and P-z/P-e = (56.2 +/- 1.5 +/- 2.6)%, could be measured simultaneousl y. The Coulomb quadrupole to magnetic dipole ratio, CMR = (-6.4 +/- 0.7(sta t) +/- 0.8(syst))%, was determined from P-x in the framework of the Mainz U nitary Isobar Model. The consistency among the reduced polarizations and th e extraction of the ratio of longitudinal-to-transverse response is discuss ed.