A multi-detector array for high energy nuclear e+e- pair spectrosocopy

K. E. Stiebing, F. W. N. de Boer, O. Froehlich, H. Bokemeyer, K. A. Mueller, K. Bethge, J. van Klinken

Submitted on 3 November 2003


A multi-detector array has been constructed for the simultaneous measurement of energy- and angular correlation of electron-positron pairs produced in internal pair conversion (IPC) of nuclear transitions up to 18 MeV. The response functions of the individual detectors have been measured with mono-energetic beams of electrons. Experimental results obtained with 1.6 MeV protons on targets containing 11B and 19F show clear IPC over a wide angular range. A comparison with GEANT simulations demonstrates that angular correlations of e+e pairs of transitions in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency to search for deviations from IPC due to the creation and subsequent decay into e+e of a hypothetical short-lived neutral boson.


Comment: 20 pages, 8 figures

Subjects: Nuclear Experiment; Astrophysics; High Energy Physics - Phenomenology