  In this article we investigate the time dependence of the gap mode of copper
nitrate at various temperatures. We combine state-of-the-art theoretical
calculations with high precision neutron resonance spin-echo measurements to
understand the anomalous decoherence effects found previously in this material.
It is shown that the time domain offers a complementary view on this
phenomenon, which allows us to directly compare experimental data and
theoretical predictions without the need of further intensive data analysis,
such as (de)convolution.
