Search for the Scalar Component of Weak Interactions

Weak interactions ar e described by the Standard Model which postulates the basic assumption about the pure " V (ector) - A (xial vector)" character of the interaction. Nevertheless, even after half a century of development of the model and experimental testing of its fundamental i ngredients, experimental data still allow the existence of other types of weak interactions - e.g. scalar interactions are ruled out only on the 7% level. Experimental project WITCH ( W eak I nteraction T rap for CH arged particles) was set up at the isoto pe separator ISOLDE at CERN trying to probe the properties of the weak interaction in order to look for their forbidden (scalar, tensor) components or at least significantly improve their current experimental limits. Experimental setup consisting of a comb ination of 2 Penning traps and retardation spectrometer allows to catch the radioactive nuclei from ISOLDE separator, traps and cools them and lets them decay in rest and then probes the energy spectrum of recoiling nuclei which is sensitive to the charact er of the weak interaction. First online measurements with the isotope 35 Ar which is very sensitive to a possible admixture of scalar interaction were performed in 2011 and 2012. The current status of the experiment and experimental results as well a s results of extensive simulations are presented and discussed here