Limits on the Fierz interference term in neutron beta decay with PERKEO III

Neutron beta decay provides an excellent toolkit for the investigation of the structure of the weak interaction and potential deviations from the predictions of the standard model of particle physics. Measuring the beta asymmetry provides the most precise way to determine the ratio of axialvector- and vector-coupling, λ, and is also sensitive to non-zero scalar and tensor couplings via the Fierz interference term, b. The neutron decay spectrometer Perkeo III was used to measure several correlation coefficients in neutron beta decay and performed the most precise measurement of the beta asymmetry at the PF1B beam at the Institut Laue-Langevin, Grenoble. In this talk we present the result of an energy-dependent analysis of the experimental beta asymmetry which yields limits on the Fierz interference term.