2019 Impact factor 2.176
Hadrons and Nuclei
Eur. Phys. J. A 1, 241-244

Short note

The angular distribution of the 12C($\gamma$,pn) reaction for E$_\gamma=120-150$ MeV

T.T-H. Yau1 - I.J.D. MacGregor1 - J. Ahrens4 - J.R.M. Annand1 - R. Beck4 - D. Branford2 - P. Grabmayr3 - S.J. Hall1 - P.D. Harty1 - T. Hehl3 - D.G. Ireland1 - J.D. Kellie1 - T. Lamparter3 - K. Livingston1 - M. Liang2, J.A. MacKenzie2 - S. McAllister1 - J.C. McGeorge1 - R.O. Owens1 - M. Sauer3 - R. Schneider3 - D.P. Watts1

1 Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
3 Department of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, UK
4 Physikalisches Institut, Universität Tübingen, D-72076 Tübingen, Germany
5 Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany

Received: 3 September 1997 / Revised version: 17 December 1997 Communicated by Th. Walcher

Abstract
The angular distribution of nucleons emitted in the 12C($\gamma$,pn) reaction has been measured using tagged photons at the Mainz microtron MAMI. The variation of the reaction strength with the polar angles of the two emitted nucleons is reported for E$_\gamma=120-150$ MeV. The proton angular distribution peaks at more backward angles than the 2H($\gamma$,p) differential cross section indicating a departure from the simple quasi-deuteron model of 2N photo-emission. The distribution shape is in reasonable agreement with microscopic theoretical models which include both $\pi$- and $\rho$-exchange.

PACS
21.30.Fe Forces in hadronic systems and effective interactions - 25.20.Lj Photoproduction reactions - 27.20.+n $6 \le A \le 19$


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