Anomalous neutron Compton scattering in Nb hydride: Indications of proton correlations

Abstract

Neutron Compton scattering probes properties of matter at time scales of the order of 10−16-10−15 s. Very strong anomalies in the cross-sections for protons were observed for scattering on NbHx and NbHxDy. The effective proton cross-section was found to vary with the time of observation (first used as a parameter in the present experiments) being reduced by 30% at times around 10−16 s but reaching its conventional value for times larger than 2·10−15 s. No conventional explanation for this anomaly (which indicates some kind of very short-lived correlations) is known. A tentative explanation is that during such short time intervals, nearby protons are quantum correlated (even at ambient temperatures) in such a manner that their neutron cross-sections are modified.