Using the Mainz 48cm\O×64cm NaI(Tl) detector and the segmented G\"ottingen recoil detector SENECA in coincidence, Compton scattering by the proton at θγlab=136∘ has been measured at MAMI (Mainz) in the energy range from 200 to 470 MeV. The new data confirm the previous observation that there is a systematic discrepancy between MAMI and LEGS (Brookhaven) data leading to different spin polarizabilities γπ=−38.7±1.8 and −27.2±3.1(×10−4fm4), respectively.
@article{arxiv.nucl-ex/0112015,
title = {Backward spin polarizability $\gamma_\pi$ of the proton},
author = {M. Camen and K. Kossert and F. Wissmann and J. Ahrens and H. -J. Arends and R. Beck and G. Caselotti and P. Grabmayr and P. D. Harty and O. Jahn and P. Jennenwein and R. Kondratiev and M. I. Levchuk and V. Lisin and A. I. L'vov and J. C. McGeorge and A. Natter and V. Olmos de León and M. Schumacher and B. Seitz and F. Smend and A. Thomas and W. Weihofen and F. Zapadtka},
journal= {arXiv preprint arXiv:nucl-ex/0112015},
year = {2013}
}