Backward spin polarizability $\gamma_\pi$ of the proton

• Main Authors: Camen, M, Kossert, K, Wissmann, F, Ahrens, J, Arends, H. -J, Beck, R, Caselotti, G, Grabmayr, P, Harty, P. D, Jahn, O, Jennenwein, P, Kondratiev, R, Levchuk, M. I, Lisin, V, L'vov, A. I, McGeorge, J. C, Natter, A, de León, V. Olmos, Schumacher, M, Seitz, B, Smend, F, Thomas, A, Weihofen, W, Zapadtka, F
• Format: Journal Article
• Language: English
• Published: 28.12.2001
• Subjects: Physics - High Energy Physics - Experiment; Physics - High Energy Physics - Phenomenology; Physics - Nuclear Experiment
• DOI: 10.48550/arxiv.nucl-ex/0112015

Phys.Rev. C65 (2002) 032202 Using the Mainz $48 cm {\O}\times 64 cm$ NaI(Tl) detector and the segmented G\"ottingen recoil detector SENECA in coincidence, Compton scattering by the proton at $\theta^{lab}_\gamma = 136^\circ$ 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 $\gamma_\pi = - 38.7 \pm 1.8$ and $-27.2 \pm 3.1$ $(\times 10^{-4}fm^4)$, respectively.