Differential cross-sections for Compton scattering from the proton hal e be
en measured at the MAMI tagged photon facility using the TAPS setup. The da
ta cover an angular range of theta (lab)(gamma) = 59 degrees -155 degrees a
nd photon energies ranging from 55 MeV to 165 MeV. Our results are in good
agreement with those from previous experiments, but yield higher precision.
Using dispersion relations the proton polarizabilities have been determine
d to be <(<alpha>)over bar> = [11.9 +/- 0.5(stat.) -/+ 1.3(syst.) +/- 0.3(m
od.)] (.) 10(-4) fm(3) and <(<beta>)over bar> = [1.2 +/- 0.7(stat.) +/- 0.3
(syst). +/- 0.4(mod.))] (.) 10(-4) fm(3). These results confirm the Baldin
sum rule which was re-evaluated to be <(<alpha>)over bar> + <(<beta>)over b
ar> = [13.8 +/- 0.4] 10(-4) fm(3). We can also conclude that there is no si
gnificant additional asymptotic contribution to the backward spin polarizab
ility gamma (pi) beyond the t-channel pi (0)-exchange.