Quasi-free Compton scattering and the polarizabilities of the neutronK. Kossert1, M. Camen1, F. Wissmann1, J. Ahrens2, J.R.M. Annand3, H.-J. Arends2, R. Beck2, G. Caselotti2, P. Grabmayr4, O. Jahn2, P. Jennewein2, M.I. Levchuk5, A.I. L'vov6, J.C. McGeorge3, A. Natter4, V. Olmos de León2, V.A. Petrun'kin6, G. Rosner3, M. Schumacher1, B. Seitz1, F. Smend1, A. Thomas2, W. Weihofen1 and F. Zapadtka1
1 II. Physikalisches Institut, Universität Göttingen, D-37073 Göttingen, Germany
2 Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
3 Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
4 Physikalisches Institut, Universität Tübingen, D-72076 Tübingen, Germany
5 B.I. Stepanov Institute of Physics, Belarussian Academy of Sciences, 220072 Minsk, Belarus
6 P.N. Lebedev Physical Institute, 117924 Moscow, Russia
(Received: 21 August 2002 / Revised version: 14 October 2002 / Published online: 11 February 2003)
Differential cross-sections for quasi-free Compton scattering from the proton and neutron bound in the deuteron have been measured using the Glasgow/Mainz photon tagging spectrometer at the Mainz MAMI accelerator together with the Mainz 48 cm 64 cm NaI(Tl) photon detector and the Göttingen SENECA recoil detector. The data cover photon energies ranging from 200 MeV to 400 MeV at . Liquid deuterium and hydrogen targets allowed direct comparison of free and quasi-free scattering from the proton. The neutron detection efficiency of the SENECA detector was measured via the reaction . The "free" proton Compton scattering cross-sections extracted from the bound proton data are in reasonable agreement with those for the free proton which gives confidence in the method to extract the differential cross-section for free scattering from quasi-free data. Differential cross-sections on the free neutron have been extracted and the difference of the electromagnetic polarizabilities of the neutron has been determined to be in units of . In combination with the polarizability sum deduced from photoabsorption data, the neutron electric and magnetic polarizabilities, and are obtained. The backward spin polarizability of the neutron was determined to be .
13.60.Fz - Elastic and Compton scattering.
14.20.Dh - Protons and neutrons.
25.20.Dc - Photon absorption and scattering.
© Società Italiana di Fisica, Springer-Verlag 2003