The WITCH (Weak Interaction Trap for CHarged particles) experiment is a retardation spectrometer coupled to a Penning trap and measures the beta-neutrino angular correlation via the shape of the recoil energy spectrum. The present form of the Standard Model describes weak processes in terms of vector and axial-vector type interactions, but the possible presence of scalar and tensor interactions is not yet ruled out. The main aim of this experiment is a test of the Standard Model for possible admixture of scalar and tensor currents. (C) 2002 Elsevier Science B.V. All rights reserved.
Beck, D., Ames, F., Beck, M., Bollen, G., Delaure, B., Deutsch, J., Dilling, J., Forstner, O., Phalet, T., Prieels, R., Quint, W., Schmidt, P., Schuurmans, P., Severijns, N., Vereecke, B., & Versyck, S. (2002). Search for new physics in beta-neutrino correlations with the WITCH spectrometer. Nuclear Physics, Section A, 701, 369C-372C. https://hdl.handle.net/2078.5/44998 (Original work published 2002)