Nuclear kinetic energies from final-state effects in the harmonic limit

This work shows a simple, yet quite powerful, data pre-treatment protocol for mass-resolved neutron spectroscopy, aimed at a better estimation of the main quantum observable linked to a nuclear-momentum distribution, its second moment. From a methodological point of view, the immediate benefit of having such a protocol is twofold. Firstly, a good estimate of a second moment of a nuclear-momentum distribution, and hence nuclear kinetic energy, provided as input for subsequent data fitting, accelerates the convergence of a data fit and minimises the likelihood of it being stuck in a non-physical solution. Secondly, it provides a simple screening tool in the search for quantum systems exhibiting statistically significant departures for a classical behaviour of equipartition of kinetic energy at any given temperature. This second benefit renders the presented protocol an important data screening tool in the search of materials exhibiting exotic properties, possibly attributed to nuclear quantum effects.